To see the other types of publications on this topic, follow the link: Thermocouples.
Journal articles on the topic 'Thermocouples'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Thermocouples.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Cai, Mengyin, Qinghuang Huang, Lingling Yue, and Peiyong Wang. "Emissivity Influence on Thermocouple Correction." Advances in Engineering Technology Research 4, no. 1 (March 20, 2023): 194. http://dx.doi.org/10.56028/aetr.4.1.194.2023.
Full textAbstract:
The reading of a thermocouple is not equal to the gas temperature because of the complicated heat transfer process among the thermocouple, the gas, and the environment. So the corrections for thermocouple measurements are necessary to obtain the real gas temperature. The current correction methods using multiple thermocouples assume that the thermocouples have the same surface emissivity. However, the emissivity of a thermocouple depends on its surface condition, and the emissivity of the thermocouples normally are different. CFD simulations are carried out to study the influence of emissivity difference on the correction accuracy. For the extrapolation method, the correction accuracy could be improved or weakened depending on the emissivity variation of the thermocouples. For the equation methods by De, the correction accuracy is poor for the low speed flow and good for the high speed flow. However, the correction accuracy for the high speed flow is weakened if the emissivity of the thermocouples have large difference. For the equation method by Brohez, the overall correction accuracy is good but the accuracy degrades greatly with the large emissivity difference of the thermocouples.
2
Fang, Cong Fu, Hui Huang, and Xi Peng Xu. "The Influence of Thermocouples on the Measurement of Grinding Temperatures." Key Engineering Materials 375-376 (March 2008): 549–52. http://dx.doi.org/10.4028/www.scientific.net/kem.375-376.549.
Full textAbstract:
An experimental investigation was conducted to reveal the influence of thermocouples on the measurement of grinding temperatures. The temperatures at the wheel-workpiece interface were measured in dry grinding using two types of foil thermocouples. It is shown that the temperatures measured by the different types or geometric parameters of thermocouples were rather different. For a specific thermocouple, the temperatures generally decreased with the reduced end-surface area of the thermocouple, which is possibly related to the reduced number of abrasives at the wheel-thermocouple interface.
3
Wu, Baoyuan, and Ge Liu. "Platinum: Platinum-Rhodium Thermocouple Wire." Platinum Metals Review 41, no. 2 (April 1, 1997): 81–85. http://dx.doi.org/10.1595/003214097x4128185.
Full textAbstract:
A new type of platinum:platinum-rhodium thermocouple wire which incorporates traces of yttrium in the platinum limb has been developed and tested in some typical working environments. This thermocouple possesses good thermal stability and mechanical strength at high temperatures, and a long service life, compared with conventional platinum:platinum-rhodium thermocouples. The thermocouple meets the output requirements of the Type S standard for thermocouples — those made of Pt:Pt-10%Rh — whose manufacturing tolerances are prescribed by the International Electrotechnical Commission (I.E.C.)(l). The life of thermocouples made from this wire is increased by around 1.5 to 2 times and they display a greater resistance to contamination.
4
Tillmann, Kokalj, Stangier, Schöppner, and Malatyali. "Effects of AlN and BCN Thin Film Multilayer Design on the Reaction Time of Ni/Ni-20Cr Thin Film Thermocouples on Thermally Sprayed Al2O3." Sensors 19, no. 15 (August 3, 2019): 3414. http://dx.doi.org/10.3390/s19153414.
Full textAbstract:
Thin film thermocouples are widely used for local temperature determinations of surfaces. However, depending on the environment in which they are used, thin film thermocouples need to be covered by a wear or oxidation resistant top layer. With regard to the utilization in wide-slit nozzles for plastic extrusion, Ni/Ni-20Cr thin film thermocouples were manufactured using direct-current (DC) magnetron sputtering combined with Aluminiumnitride (AlN) and Boron-Carbonitride (BCN) thin films. On the one hand, the deposition parameters of the nitride layers were varied to affect the chemical composition and morphology of the AlN and BCN thin films. On the other hand, the position of the nitride layers (below the thermocouple, above the thermocouple, around the thermocouple) was changed. Both factors were investigated concerning the influence on the Seebeck coefficient and the reaction behaviour of the thermocouples. Therefore, the impact of the nitride thin films on the morphology, physical structure, crystallite size, electrical resistance and hardness of the Ni and Ni-20Cr thin films is analysed. The investigations reveal that the Seebeck coefficient is not affected by the different architectures of the thermocouples. Nevertheless, the reaction time of the thermocouples can be significantly improved by adding a thermal conductive top coat over the thin films, whereas the top coat should have a coarse structure and low nitrogen content.
5
Yasser Abdelaziz, Mahmoud Hammam, Faten Megahed, and Ebtesam Qamar. "Characterizing Drift Behavior in Type K and N Thermocouples After High Temperature Thermal Exposures." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 97, no. 1 (August 13, 2022): 62–74. http://dx.doi.org/10.37934/arfmts.97.1.6274.
Full textAbstract:
Although of the widespread use of base metal thermocouples in the industry, many previous relevant researches have shown that the accuracy and stability of thermocouples are clearly influenced by any physical or chemical changes in their thermoelements. Among the most important of these changes are the inhomogeneity, pollution, oxidation and microstructure changes of the thermoelements, all of these changes and more leads to thermocouples drift after a prolonged thermal exposure. To study how these changes affect the drift and thermoelectric properties of thermocouples, in this work we subjected the base metal thermocouples of types K and N to successive thermal exposure periods at their maximum temperatures. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) systems were used to monitor the change in the crystal structure and chemical composition of the thermocouple wires after each stage of the thermal heating, and then we studied the changes in the thermoelectric properties of thermocouple wires. The results showed type N thermocouples are more stable at high temperatures (up to 1050 ͦ C), even if used for long periods (for more than 1200 hours) at those temperatures, but K type thermocouples showed a rapid drift with first exposure to high temperatures and completely failed after 600 hours due to devastating corrosion.
6
Hatmoko, Sumantri Hatmoko, Kussigit Santosa Santosa, Giarno Giarno Giarno, Dedy Haryanto Haryanto, Mulya Juarsa Juarsa, M. Hadi Kusuma, Anhar Riza Antariksawan, and Surip Widodo Widodo. "KARAKTERISASI TERMOKOPEL TIPE K PADA FASILITAS SIMULASI SISTEM FASSIP-02." POROS 16, no. 2 (August 27, 2021): 127. http://dx.doi.org/10.24912/poros.v16i2.11651.
Full textAbstract:
In the activities of the Pratama Insinas, Ministry of Higher Education technology research in 2018, PTKRN BATAN built a testing facility that simulates a passive cooling system on the reactor core when there is a loss of outside power. The test facility is the Passive-02 System Simulation Facility (FASSIP02).In FASSIP-02 there are several parameters that need to be measured, one of which is temperature. In the measurement of temperature using a K type Thermocouple Connected to the National Instrument 9178 and 9213 modules that use computer programming with LabVIEW software. Temperature measurements need to be characterized.Characterization of type K thermocouples was carried out using thermobaths, 30 type K thermocouples, standard thermocouples,National Instrument modules 9178 and 9213 with computer programming displays using LabVIEW software. The method used for characterization oftype K thermocouples is a fixed temperature comparison method where the results of the temperature control of thermobath is 30-90 ͦC compared with the results of measurements from the type Kthermocouple and standard thermocouple. From the difference of the copper-wrapped junction tip thermocouple without the copper-wrapped and standard thermocouple produces a small error value, so the use of copper as a thermocouple junction end wrapper can be used as a temperature measurement FASSIP-02.
7
Krille, Tobias, Rico Poser, Markus Diel, and Jens von Wolfersdorf. "Conduction and Inertia Correction for Transient Thermocouple Measurements. Part II: Experimental Validation and Application." E3S Web of Conferences 345 (2022): 01003. http://dx.doi.org/10.1051/e3sconf/202234501003.
Full textAbstract:
Thermocouples are often used for temperature measurements. Under transient conditions, measurement errors can occur due to capacitive inertia and heat conduction along the stem of the thermocouples. To correct such errors, a method is presented in Part I [1] of this paper, which uses a simplified analytical approach and a numerical solution. In the present work, this method is applied to temperature measurements. Several experiments with different thermocouple designs were performed to investigate different conditions such as installation depth, thermocouple type and transient temperature rises. In all cases, two thermocouples were placed so that they are exposed to the same fluid temperature. They are installed with short or long immersion length, respectively. It is shown that only the short thermocouple experiences a thermal conduction error, but both are subject to thermal inertia. The importance of compensating for these effects is shown by quantifying the errors in a typical heat transfer experiment when they are neglected. It is shown, which parameters are necessary for a re-calculation of fluid temperatures when two thermocouples are present at the same measuring position. Furthermore, a simplified method is described, which can be applied if the instrumentation of only one thermocouple is possible.
8
Jutte, Lisa S., Kenneth L. Knight, and Blaine C. Long. "Reliability and Validity of Electrothermometers and Associated Thermocouples." Journal of Sport Rehabilitation 17, no. 1 (February 2008): 50–59. http://dx.doi.org/10.1123/jsr.17.1.50.
Full textAbstract:
Objective:Examine thermocouple model uncertainty (reliability + validity).Design:First, a 3 × 3 repeated measures design with independent variables electrothermometers and thermocouple model. Second, a 1 × 3 repeated measures design with independent variable subprobe.Intervention:Three electrothermometers, 3 thermocouple models, a multi-sensor probe and a mercury thermometer measured a stable water bath.Main Outcome Measures:Temperature and absolute temperature differences between thermocouples and a mercury thermometer.Results:Thermocouple uncertainty was greater than manufactures’ claims. For all thermocouple models, validity and reliability were better in the Iso-Themex than the Datalogger, but there were no practical differences between models within an electrothermometers. Validity of multi-sensor probes and thermocouples within a probe were not different but were greater than manufacturers’ claims. Reliability of multiprobes and thermocouples within a probe were within manufacturers claims.Conclusion:Thermocouple models vary in reliability and validity. Scientists should test and report the uncertainty of their equipment rather than depending on manufactures’ claims.
9
Tszeng, T. C., and V. Saraf. "A Study of Fin Effects in the Measurement of Temperature Using Surface-Mounted Thermocouples." Journal of Heat Transfer 125, no. 5 (September 23, 2003): 926–35. http://dx.doi.org/10.1115/1.1597622.
Full textAbstract:
The present study addresses the effects of thermocouples on the measured temperature when such thermocouples are mounted directly on the surface of the object. A surface-mounted thermocouple is a very convenient way of measuring the surface temperature. However, the heat conduction into/from the thermocouple wire changes the local temperature at the thermocouple junctions along with the immediate vicinity of the thermocouple. As a consequence, the emf appearing at the thermocouple terminals does not correspond to the actual surface temperature. In this paper, we first discuss the general characteristics of the enhanced heating/cooling due to the so-called “fin effects” associated with the surface-mounted thermocouples. An embedded computational model is then developed so that the model can be used in conjunction with a regular FEM model for the multidimensional calculation of the heating or cooling of a part. The embedded computational model is shown to offer very accurate calculation of the temperature at the junction of thermocouple wire. The developed computational model is further used in the inverse heat transfer calculation for a Jominy end quench experiment.
10
Shen, Yi-Xuan, Yao-Chuan Tsai, Chi-Yuan Lee, Chyan-Chyi Wu, and Ching-Liang Dai. "Thermoelectric Energy Micro Harvesters with Temperature Sensors Manufactured Utilizing the CMOS-MEMS Technique." Micromachines 13, no. 8 (August 5, 2022): 1258. http://dx.doi.org/10.3390/mi13081258.
Full textAbstract:
This study develops a TEMH (thermoelectric energy micro harvester) chip utilizing a commercial 0.18 μm CMOS (complementary metal oxide semiconductor) process. The chip contains a TEMH and temperature sensors. The TEMH is established using a series of 54 thermocouples. The use of the temperature sensors monitors the temperature of the thermocouples. One temperature sensor is set near the cold part of the thermocouples, and the other is set near the hot part of the thermocouples. The performance of the TEMH relies on the TD (temperature difference) at the CHP (cold and hot parts) of the thermocouples. The more the TD at the CHP of the thermocouples increases, the higher the output voltage and output power of the TEMH become. To obtain a higher TD, the cold part of the thermocouples is designed as a suspended structure and is combined with cooling sheets to increase heat dissipation. The cooling sheet is constructed of a stack of aluminum layers and is mounted above the cold part of the thermocouple. A finite element method software, ANSYS, is utilized to compute the temperature distribution of the TEMH. The TEMH requires a post-process to obtain the suspended thermocouple structure. The post-process utilizes an RIE (reactive ion etch) to etch the two sacrificial materials, which are silicon dioxide and silicon substrate. The results reveal that the structure of the thermocouples is completely suspended and does not show any injury. The measured results reveal that the output voltage of the TEMH is 32.5 mV when the TD between the CHP of the thermocouples is 4 K. The TEMH has a voltage factor of 8.93 mV/mm2K. When the TD between the CHP of the thermocouples is 4 K, the maximum output power of the TEMH is 4.67 nW. The TEMH has a power factor of 0.31 nW/mm2K2.
11
Liu, Zhihui, Tengda Guo, Yongjun Cheng, Bi Wang, Kai Shen, Kai Hu, Jiankang Zhou, Chuanbing Zhang, Zixi Wang, and Wanyu Ding. "Mechanism of Seebeck coefficient variation at the output of NiCr/NiSi thin film thermocouple with different wires." Journal of Physics: Conference Series 2724, no. 1 (March 1, 2024): 012001. http://dx.doi.org/10.1088/1742-6596/2724/1/012001.
Full textAbstract:
Abstract In this paper, by using magnetron sputtering to prepare NiCr/NiSi thin film thermocouples, the static calibration method is used for NiCr/NiSi thermocouples with rapid temperature calibration experiments. Different temperature calibration curves are obtained. The Seebeck coefficient of NiCr/NiSi thin film thermocouples connected to NiCr/NiSi wires is significantly higher (41.39 μV/°C) than that of NiCr/NiSi wires (0 μV/°C). The Seebeck coefficient (41.39 μV/°C) of the NiCr/NiSi thin-film thermocouple connected to copper wire is significantly higher than that of the thermocouple connected to copper wire (0 μV/°C). The problem of the Seebeck coefficient of the K-type thermocouple is analyzed by experimental data, which provides the relevant parameter basis for the use of the K-type thermocouple. The method has the advantages of simple equipment, convenient operation, accurate and reliable data, and provides a basis for the sensor to measure the temperature measurement.
12
Offenzeller, Christina, Marcel Knoll, Bernhard Jakoby, and Wolfgang Hilber. "Screen-Printed, Pure Carbon-Black Thermocouple Fabrication and Seebeck Coefficients." Sensors 19, no. 2 (January 19, 2019): 403. http://dx.doi.org/10.3390/s19020403.
Full textAbstract:
Thermocouples classically consist of two metals or semiconductor components that are joined at one end, where temperature is measured. Carbon black is a low-cost semiconductor with a Seebeck coefficient that depends on the structure of the carbon particles. Different carbon black screen-printing inks generally exhibit different Seebeck coefficients, and two can therefore be combined to realize a thermocouple. In this work, we used a set of four different commercially available carbon-black screen-printing inks to print all-carbon-black thermocouples. The outputs of these thermocouples were characterized and their Seebeck coefficients determined. We found that the outputs of pure carbon-black thermocouples are reasonably stable, linear, and quantitatively comparable to those of commercially available R- or S-type thermocouples. It is thus possible to fabricate thermocouples by an easily scalable, cost-efficient process that combines two low-cost materials.
13
Tucker, D. J. L., F. Edler, V. Žužek, J. Bojkovski, C. Garcia-Izquierdo, M. Parrondo, L. Šindelářová, and N. Arifovic. "Thermoelectric stability of dual-wall and conventional type K and N thermocouples." Measurement Science and Technology 33, no. 7 (April 5, 2022): 075003. http://dx.doi.org/10.1088/1361-6501/ac57ee.
Full textAbstract:
Abstract Mineral insulated metal sheathed (MIMS) base metal thermocouples experience thermoelectric drift over their lifetime caused by use at high temperatures and metallurgical changes, causing spurious measurement errors. CCPI Europe Limited and University of Cambridge have designed a MIMS thermocouple with an additional inner sheath, in order to protect the thermoelements from the effects that cause thermoelectric drift. The performance of these dual-wall thermocouples and conventional type N and type K thermocouples are assessed at six different National Metrology Institutes (NMIs) using two different testing regimes: isothermal testing at 1200 °C, and thermal cycling tests between 300 °C and 1150 °C. The investigation demonstrates that in both testing regimes, the type N dual-wall thermocouples showed a significantly reduced thermoelectric drift by about a factor of three compared to the conventional thermocouples. There was no significant difference between the type K dual-wall and conventional type K thermocouples in the isothermal tests, and the type K dual-wall thermocouples showed greater drift than the conventional thermocouples in the thermal cycling tests, but the conventional type K thermocouples were less robust than the dual-wall type K thermocouples. The results presented in this paper represent an impartial assessment of the thermoelectric stability of both dual-wall thermocouples and conventional thermocouples, which may provide assurance to potential users.
14
You, Fang Yi, and Qiu Lian Dai. "The Study on Optimum Thickness of Thermocouple Used for Measuring the Grinding Temperatures of Brittle Materials." Applied Mechanics and Materials 670-671 (October 2014): 1296–300. http://dx.doi.org/10.4028/www.scientific.net/amm.670-671.1296.
Full textAbstract:
The grinding temperatures were measured with half-cylindrical thermocouple which made by grinding method and measrued with foil thermocouple which made by rolling method respectively when grinding brittle granite with an Al2O3 wheel. Experimental results include average grinding zone temperatures and grains’ temperatures were analysed. The deviation of average grinding zone temperatures measured by them were within 6%. The foil thermocouples do not easily to lap due to the brittleness of the workpiece which usually makes the joint of thermocouples disconnected. But half-cylindrical thermocouples are more convenient to be prepared and be used than foil ones. However, the periodic “flash” impulses which reflect the grains’ temperature measured by half-cylindrical thermocouple were about 51% lower than the others. According to time constant, the thickness of the thermocouple less than 0.007mm is a necessary condition for measure the grains’ temperatures without distortion. The half-cylindrical thermocouple is too thick to have a momentary response time thus makes it out of the measurement accuracy range when it is used to measure the temperature of the grains. Therefore, foil thermocouple has an optimum thickness of 0.007mm is suitable for measuring the grains’ temperature while half-cylindrical thermocouple with average thickness less than 0.12mm is suitable for measuring the average grinding zone temperature.
15
Alaya, Mohamed Amine, Viktória Megyeri, David Bušek, Gábor Harsányi, and Attila Geczy. "Effect of different thermocouple constructions on heat-level vapour phase soldering profiles." Soldering & Surface Mount Technology 32, no. 4 (March 31, 2020): 253–59. http://dx.doi.org/10.1108/ssmt-10-2019-0034.
Full textAbstract:
Purpose To improve productivity and reach better quality in assembling, measurements and proper process controlling are a necessary factor. This study aims to focus on the monitoring heat-level-based vapour phase reflow soldering (VPS), where – as it was found – different thermocouple constructions can affect the set parameters of the oven and resulting soldering profiles significantly. Design/methodology/approach The study experiments showed significant alteration of the heating profiles during the process of the reflowing using different construction of k-type thermocouples. In a heat-level-based VPS oven, polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA) gas and water-resistant, fibreglass, thin PFA and ultrathin PFA-covered thermocouples were tested with ±1 °C precision. The oven parameters were swept according to the heating power; the length of the introduced thermocouple cables was also taken into account. An FR4-based sample PCB was used for monitoring the temperature. Findings According to the results, due to the mass and volume of the thermocouples’ wires, different transients were observed on the resulting soldering profiles on the same sample PCB. The thermocouples with lower thermal mass result in faster profiles and significantly different heating factor values compared to the thermocouples that have larger thermal mass. Consequently, the length of the thermocouple wires put in the oven has also considerable effect on the heat transfer of the PCB inside the oven as well. Originality/value The paper shows that the thermocouple construction must be taken into account when setting up a required soldering profile, while the thermal mass of the wires might cause a significant difference in the prediction of the actual and expected soldering temperatures.
16
Zeng, Qiyong, Baoyuan Sun, Jing Xu, Xinlu Deng, Jun Xu, and Ying Jia. "Development of NiCr∕NiSi Thin-Film Thermocouple Sensor for Workpiece Temperature Measurement in Chemical Explosive Material Machining." Journal of Manufacturing Science and Engineering 128, no. 1 (June 2, 2005): 175–79. http://dx.doi.org/10.1115/1.2117467.
Full textAbstract:
Temperature plays a vital role in the machining industry today. With increasing cutting speeds being used in machining operations, the thermal aspects of cutting have become more important. A nickel-chrome versus nickel-silicon thin-film thermocouple system has been established for measuring instantaneous workpiece temperature in chemical explosive material machining. The thin-film thermocouples have been directly deposited inside high-speed steel cutters by means of multiple arc ion plating and the thickness of the thermocouple junction is only a few micrometers. The research effort has been concentrated on developing solutions to the insulating problem between the thin-film thermocouples and the high-speed steel cutters. SiO2 insulating films have been deposited on the high-speed steel substrates by microwave electron cyclotron resonance plasma source enhanced radiofrequency (rf) reactive magnetron sputtering. Static and dynamic calibrations of the NiCr∕NiSi thin-film thermocouples are presented. The results of the testing indicate that the thin-film thermocouples have good linearity, little response time, and perform excellently when machining in situ.
17
Tuz, Yulian, Oleh Kozyr, and Yuriy Samartsev. "Features of temperature measurement of short thermal pulses." Ukrainian Metrological Journal, no. 1 (March 31, 2021): 46–52. http://dx.doi.org/10.24027/2306-7039.1.2021.228237.
Full textAbstract:
Short thermal impulses are typical for the explosions, glowing combustion products, which are accompanied by high pressure and destructive force. The most suitable thermocouples for measuring temperature values of a high-speed thermal process are thermocouples with known dynamic characteristics, which record the value of the output EMF during the temperature change transient process. Hourly dependence of the input temperature is calculated by converting from the operator to hourly form or from the hourly dependence through the inverted convolution of the output signal with the pulse transient characteristic by numerical methods.
Restoration of the values of temperature acting on them is done by EMF measured values processing using the well-known dynamic characteristics of thermocouples, which are suggested to be pre-determined in the form of magnitude and phase frequency response, by heating the thermocouple with a sinusoidal electric current of the appropriate frequency. To be able to implement the method of determining the characteristics of thermocouple dynamics, a model of the processes that occur in the thermocouple when electric current is passing through it is presented. The use of sinusoidal electric current to heat up the thermocouple leads to the appearance of a DC component and a component with second harmonic in the output of EMF. On the basis of the proposed model, the algorithm of obtaining the magnitude and phase frequency response of the thermocouple by means of determining the ratio of the amplitudes of the EMF variable of the thermocouple in the form of a composition at the double frequency of the input current to the amplitude of the second harmonic of the input current, obtained by means of elevation to the square of output EMF instantaneous values by the calculating method, is developed.
The methodology was developed, a research system was created, and experimental samples of the fast thermocouples were made. The obtained dynamic characteristics allow, by applying the inverse function, to adequately measure the current temperature of thermal impulses using the data of the output thermal EMF of thermocouples.
Keywords: measurement; temperature; thermal pulse; thermocouple; dynamic characteristics; Nyquist plot.
18
Wang, Tingting, Yajun Yan, Yiwen Yuan, Zhuang Ma, Ailiang Zhang, Youyu Chen, and Yimin Yu. "An effective method for quality control of the thermocouple." MATEC Web of Conferences 173 (2018): 01029. http://dx.doi.org/10.1051/matecconf/201817301029.
Full textAbstract:
As a basic testing element, the thermocouples are widely used in the safety and energy efficiency testing of the electronic and electrical products, new energy products and so on. The accuracy of all thermocouples can't be assured for they are mostly calibrated by sampling. In view of this situation, an efficient and convenient method for the intermediate check of the thermocouple is proposed in this paper. Taking 0 degree and 100 degree which can be easily obtained in the nature as the reference standard temperature, the deviation of the testing thermocouples and the reference standard temperature can be determined and the qualification rate of the thermocouples can be obtained. This method can promote the quality control of the laboratory.
19
Safina, I. A., and S. A. Artemyeva. "Prediction of Dynamic Characteristics of Thermocouples with Thin-Wire Sensing Elements." Devices and Methods of Measurements 13, no. 2 (July 6, 2022): 83–92. http://dx.doi.org/10.21122/2220-9506-2022-13-2-83-92.
Full textAbstract:
Thermocouples dynamic characteristicsʼ prediction is one of the relevant directions in the field of dynamic measurements of non-stationary temperatures of liquid and gaseous media. Thermocouples dynamic characteristicsʼ prediction makes it possible to provide effective continuous correction in automatic control systems for non-stationary temperatures. The purpose of this paper was to develop a theoretically justified relation linking the current or expected time constant of fine-wire thermocouples with the known time constant established at known parameters of liquid and gaseous media.A formula linking the time constant of fine-wire thermocouples with the conditions of heat exchange with the measured medium and the thermophysical characteristics of the thermocouple sensing elements has been deducted. An approximate formula is also given for calculating the internal resistance of wire sensing elements of thermocouples, which must be considered when calculating the time constant of a thermocouple. In consideration of the obtained formulas, a multi-parameter relation linking the current or expected time constant of fine-wire thermocouples with the known time constant set at the known parameters of the measured media has been formed.It is suggested to simplify the formed multi-parameter relation and make it dependent, for example, on the “expected velocity of the measured medium × expected density of the measured medium” complex (Vm2 ρm2 ). Simplified relations in the form of hyperbolic functions with constant parameters and argument in the form of Vm2 ρm2 complex were obtained for airflowat different temperatures, pressures, and velocities.On the example of airflow, it is shown that the complex multi-parametric relation linking the expectedand known time constants of thermocouples can be simplified to a hyperbolic dependence, where the argument can be the Vm2 ρm2 complex. Moreover, the degree of approximation of hyperbolic dependencies to the exact values of the multi-parametric relation can reach the R-square = 0.9592 criterion.A multi-parametric relation has been proposed. That relates the known time constant of a thermocouple to the expected or current time constant of the same thermocouple at other parameters of the measured medium from the point of view of the heat exchange and thermal conduction theory. The proposed relation can be used in automatic control systems of non-stationary temperature of various liquid or gaseous media to provide continuous correction of thermocouples dynamic characteristics. Depending on the number of measured medium parameters, the suggested multi-parameter relation can be replaced by simplified relations with other complexes containing, for example, density, velocity, flow rate and pressure of the measured medium.
20
Long, Blaine C., Lisa S. Jutte, and Kenneth L. Knight. "Response of Thermocouples Interfaced to Electrothermometers When Immersed in 5 Water Bath Temperatures." Journal of Athletic Training 45, no. 4 (July 1, 2010): 338–43. http://dx.doi.org/10.4085/1062-6050-45.4.338.
Full textAbstract:
Abstract Context: Thermocouples and electrothermometers are used in therapeutic modality research. Until recently, researchers assumed that these instruments were valid and reliable. Objective: To examine 3 different thermocouple types in 5°C, 15°C, 18.4°C, 25°C, and 35°C water baths. Design: Randomized controlled trial. Setting: Therapeutic modality laboratory. Intervention(s): Eighteen thermocouple leads were inserted through the wall of a foamed polystyrene cooler. The cooler was filled with water. Six thermocouples (2 of each model) were plugged into the 6 channels of the Datalogger and 6 randomly selected channels in the 2 Iso-Thermexes. A mercury thermometer was immersed into the water and was read every 10 seconds for 4 minutes during each of 6 trials. The entire process was repeated for each of 5 water bath temperatures (5°C, 15°C, 18.4°C, 25°C, 35°C). Main Outcome Measure(s): Temperature and absolute temperature differences among 3 thermocouple types (IT-21, IT-18, PT-6) and 3 electrothermometers (Datalogger, Iso-Thermex calibrated from −50°C to 50°C, Iso-Thermex calibrated from −20°C to 80°C). Results: Validity and reliability were dependent on thermocouple type, electrothermometer, and water bath temperature (P < .001; modified Levene P < .05). Statistically, the IT-18 and PT-6 thermocouples were not reliable in each electrothermometer; however, these differences were not practically different from each other. The PT-6 thermocouples were more valid than the IT-18s, and both thermocouple types were more valid than the IT-21s, regardless of water bath temperature (P < .001). Conclusions: The validity and reliability of thermocouples interfaced to an electrothermometer under experimental conditions should be tested before data collection. We also recommend that investigators report the validity, the reliability, and the calculated uncertainty (validity + reliability) of their temperature measurements for therapeutic modalities research. With this information, investigators and clinicians will be better able to interpret and compare results and conclusions.
21
Cui, Y., Y. Xie, and J. Yin. "Research of transient temperature measuring based on thin-film thermocouple and Wi-Fi wireless DAQ method." Journal of Instrumentation 18, no. 02 (February 1, 2023): P02021. http://dx.doi.org/10.1088/1748-0221/18/02/p02021.
Full textAbstract:
Abstract The thin-film thermocouple temperature sensor is a new type of temperature sensor which was emerged with the development of thin-film materials. It features on a small heat capacity and a rapid response speed for transient temperature measurement on the surface of objects. The existing temperature data acquisition systems for filamentary thermocouples do not yet meet the conditions for distortion-free measurement of transient temperature signals in terms of sampling frequency and transmission rate. In addition, it is less flexible in terms of data transmission methods, while the cold end of the thermocouple compensation method has not yet compensated for the non-linear phenomenon of thermocouples, which affects the final measurement accuracy. This paper devised a wireless temperature data acquisition system for K-type thin-film thermocouples using a Wi-Fi wireless network to transmit sampling data, then applied the devised system as a data acquisition method to investigate the measurement of transient temperatures in conjunction with thin-film thermocouple sensors. The results of performance test indicated that the devised system is capable of transient temperature measurement of K-type thin-film thermocouples in the range of 0–650°C with a maximum sampling rate of 100 kHz, a temperature resolution of 0.16 degrees Celsius, an accuracy of 0.2% after non-linear compensation and the ability to measure transient temperature signals with a maximum frequency component of 25 kHz. Taken advantage of the devised wireless data acquisition system to measure the impulse response of a thin-film thermocouple sensor specimen, the meausured response curve is consistent with the law of first-order system, and the time constant of the sensor was obtained as approximately 1.16 ms. A comparison between the existing data acquisition apparatuses of type K thermocouple was made. The limitations of the devised system are also discussed.
22
Yakaboylu, Gunes, Rajalekshmi Pillai, Katarzyna Sabolsky, and Edward Sabolsky. "Fabrication and Thermoelectric Characterization of Transition Metal Silicide-Based Composite Thermocouples." Sensors 18, no. 11 (November 3, 2018): 3759. http://dx.doi.org/10.3390/s18113759.
Full textAbstract:
Metal silicide-based thermocouples were fabricated by screen printing thick films of the powder compositions onto alumina tapes followed by lamination and sintering processes. The legs of the embedded thermocouples were composed of composite compositions consisting of MoSi2, WSi2, ZrSi2, or TaSi2 with an additional 10 vol % Al2O3 to form a silicide–oxide composite. The structural and high-temperature thermoelectric properties of the composite thermocouples were examined using X-ray diffraction, scanning electron microscopy and a typical hot–cold junction measurement technique. MoSi2-Al2O3 and WSi2-Al2O3 composites exhibited higher intrinsic Seebeck coefficients (22.2–30.0 µV/K) at high-temperature gradients, which were calculated from the thermoelectric data of composite//Pt thermocouples. The composite thermocouples generated a thermoelectric voltage up to 16.0 mV at high-temperature gradients. The MoSi2-Al2O3//TaSi2-Al2O3 thermocouple displayed a better performance at high temperatures. The Seebeck coefficients of composite thermocouples were found to range between 20.9 and 73.0 µV/K at a temperature gradient of 1000 °C. There was a significant difference between the calculated and measured Seebeck coefficients of these thermocouples, which indicated the significant influence of secondary silicide phases (e.g., Mo5Si3, Ta5Si3) and possible local compositional changes on the overall thermoelectric response. The thermoelectric performance, high sensitivity, and cost efficiency of metal silicide–alumina ceramic composite thermocouples showed promise for high-temperature and harsh-environment sensing applications.
23
Skifton, Richard, Joe Palmer, and Alex Hashemian. "Optimized High-Temperature Irradiation-Resistant Thermocouple for Fast-Response Measurements." EPJ Web of Conferences 253 (2021): 06004. http://dx.doi.org/10.1051/epjconf/202125306004.
Full textAbstract:
The high-temperature irradiation-resistant thermocouple is the only temperature probe proven to withstand the high-temperature (>1290°C), high-radiation (a fluence of up to ∼1 × 1021 n/cm2) environments of nuclear reactor fuel design testing and/or over-temperature accident conditions. This report describes the improved performance of a molybdenum and niobium thermocouple by utilizing a coaxial design (i.e., a single wire grounded to the outer sheath). This optimized high-temperature irradiation-resistant thermocouple features a simplified design yet allows for more robust individual components. The niobium and molybdenum thermoelements can be used interchangeably in either the sheath or wire, depending on the intended application. Via a plunge test in flowing water, the response time of the coaxial build of the high-temperature irradiation-resistant thermocouple was determined to be 30x faster than that of the comparable ungrounded type-K thermocouples, and 10x faster than the grounded type-K thermocouples and traditional ungrounded high-temperature irradiation-resistant thermocouples (i.e., two-wire configurations). Furthermore, by capitalizing on the coaxial design, a multi-core high-temperature irradiation-resistant probe with multiple “single-pole” wires along the length of the sheath was proven feasible. This multi-core, thermocouple design was dubbed a “demicouple.” The high-temperature irradiation-resistant demicouple is primarily applied during fuel experiments to record multiple fuel-pin centerline temperature measurements using a single compact sensor. Furthermore, the shared “common” leg between demicouple junctions reduces error propagation in secondary measurements such as temperature differentials.
24
Zeng, Qi Yong, Tao Hong, Le Chen, and Yun Xian Cui. "Magnetron Sputtering of NiCr/NiSi Thin-Film Thermocouple Sensor for Temperature Measurement when Machining Chemical Explosive Material." Key Engineering Materials 467-469 (February 2011): 134–39. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.134.
Full textAbstract:
Temperature plays a vital role in the machining industry today. A Nickel-Chrome versus Nickel-Silicon thin-film thermocouple system has been established for measuring instantaneous workpiece temperature in chemical explosive material machining. The NiCr/NiSi thin-film thermocouples have been deposited inside high speed steel cutters by magnetron sputtering. The typical deposition conditions are summarized. Static and dynamic calibrations of the NiCr/NiSi thin-film thermocouples are presented. The Seebeck coefficient of the TFTC is 40.4 μV/°C which is almost the same as that of NiCr/NiSi wire thermocouple. The response time is about 0.42ms. The testing results indicate that the developed NiCr/NiSi thin-film thermocouple sensors can respond fast enough to catch the very short temperature pulse and perform excellently when machining chemical explosive material in situ.
25
Slašťan, Kristián, Jozef Svetlík, Milan Konárik, and Martin Boroš. "Identifying Effect of Car Fire Blankets on Chosen Fire Parameter Using Large-Scale Fire Tests of Internal Combustion Engine Vehicle and High-Voltage Traction Battery—Comparative Slovak Case Study." Applied Sciences 14, no. 11 (June 5, 2024): 4902. http://dx.doi.org/10.3390/app14114902.
Full textAbstract:
Firefighting units in the Slovak Republic are well prepared for extinguishing fires of vehicles with internal combustion engines. However, the expansion of electromobility is also coming to Slovakia. It is essential to pay attention to this topic from the point of view of repression. This article deals with car fire blankets. The main objective is to verify and compare the effectiveness of extinguishing internal combustion engine vehicle (ICEV) fires and high-voltage traction battery (HTB) fires using car fire blankets. The effectiveness of a car fire blanket was determined based on the analysis of temperature drops during large-scale fire tests of ICEVs and HTBs. The temperature was recorded by four thermocouples. Two thermocouples were placed at 0.7 m from the ICEV and HTB; one thermocouple was placed in the interior of the ICEV and inside the HTB; one thermocouple was placed on the roof of the ICEV and the surface of the HTB. Subsequently, the results were compared based on temperature–time curves obtained from experimental measurements. Applying the car fire blanket to the ICEV fire caused a drop in temperature on all thermocouples. The most significant temperature drop was recorded in the interior of the vehicle. Specifically, the temperature dropped from 724 °C to 140 °C. However, the application of the car fire blanket had a different effect on the HTB fire. There was a minimal temperature change in the thermocouple on the right side at a 0.7 distance. The other thermocouples identified a slight increase in temperature.
26
Zhao, Guo Chang, Chun Lei Zhao, Li Ping Song, and Xian Yi Tong. "Research on and Applications of Au/Pt Thermocouples." Applied Mechanics and Materials 483 (December 2013): 105–9. http://dx.doi.org/10.4028/www.scientific.net/amm.483.105.
Full textAbstract:
Elemental thermocouples are capable of meeting the demanding requirements of high temperature measurement with high accuracy, wide temperature measurement range, and long operational life. With an ever increasing need for more accurate, more precise temperature measuring devices over a wide spectrum of temperatures, elemental thermocouples show great promise when compared with its counterparts. The Au/Pt thermocouple, one of the more effective elemental metal combinations, is the ideal standard thermometer in the range of 0°C - 1000°C due to its reproducibility, accuracy, stability, and durability, causing the US and Korea to standardize its use. Much academic work has been done on the accuracy, stability, thermoelectric properties, structural design, and calibration methods of Au/Pt thermocouples to develop it to its current state. This paper summarizes research done on Au/Pt thermocouples, both domestically and internationally, in order to provide a foundation for future improvement.
27
Abouellail, A. A., I. I. Obach, A. A. Soldatov, P. V. Sorokin, and A. I. Soldatov. "Research of Thermocouple Electrical Characteristics." Materials Science Forum 938 (October 2018): 104–11. http://dx.doi.org/10.4028/www.scientific.net/msf.938.104.
Full textAbstract:
This paper presents the results of the experimental research on the electrical characteristics of two dissimilar thermoelectric power sources. Chromel-alumel and nichrome-constantan are the investigated types of thermocouples that are utilized as thermopower sources. Through the assistance of the collected data, experimental and theoretical studies of two equivalent thermopower sources are done. The first studied source is obtained by a parallel connection of the two types of thermocouples, and the second studied source is achieved by the parallel connection of two thermocouples of nichrome-constantan and a single thermocouple made of chromel-alumel. Theoretical studies of the two equivalent thermoelectric sources proved good repeatable precision of the studied results of experimental measurements.
28
Markowski, Piotr M. "Multilayer thick-film thermoelectric microgenerator based on LTCC technology." Microelectronics International 33, no. 3 (August 1, 2016): 155–61. http://dx.doi.org/10.1108/mi-05-2016-0038.
Full textAbstract:
Purpose The purpose of this paper was to develop the methodology of thick-film/low temperature co-fired ceramic (LTCC) multilayer thermoelectric microgenerator fabrication including the procedure of silver-nickel thermocouples integration with LTCC. Design/methodology/approach To miniaturize the structures and to increase the output parameters (generated voltage, electrical power), the microgenerator was designed as multilayer systems. It allows to reduce size of the system and to increase the number of thermocouples integrated inside the structure. It also protects buried thermocouples against exposure to harmful external factors (e.g. moisture, oxidation and mechanical exposures). As a substrate, LTCC was used. For the thermocouples fabrication, thick-film pastes based on silver and nickel were chosen. Ag/Ni thermocouple has nearly three times higher Seebeck coefficient and 30 per cent lower electrical resistance than the combination of Ag/PdAg used in previous works of the author. Findings A multi-layer thick-film thermoelectric generator based on LTCC and Ag, Ni pastes was fabricated. Thirty Ag/Ni thermocouples were precisely screen-printed on few layers. Thermocouples’ arms are 15 mm long and about 150 μm wide. Interlayer connections (via-holes filled with conductive paste) provided the electrical contact between the layers. The biggest fabricated harvester consisted of 90 miniature thermocouples buried inside the LTCC. Originality/value The paper presents the results of research that provided to optimize the co-firing process of the LTCC/Ni set. In the result, the methodology of co-firing of silver-nickel thermocouples and LTCC ceramic was elaborated. Also, the methodology of fabrication of miniature thermoelectric energy harvesters was optimized.
29
Shinozuka, Jun, and Habibah binti Jaharadak. "Measurement of the Temperature Distribution at the Tool-Chip Interface by Using a Cutting Tool with Seven Pairs of Built-In Micro Cu/Ni Thermocouples." Advanced Materials Research 1136 (January 2016): 586–91. http://dx.doi.org/10.4028/www.scientific.net/amr.1136.586.
Full textAbstract:
Knowing temperatures at the tool-chip interface is extremely important to optimize the machining condition and to improve the machining performance, furthermore to design high performance materials. In order to grasp the temperature distribution at the tool-chip interface, this study has devised an indexable insert with seven pairs of built-in micro Cu/Ni thermocouples on the rake face near the cutting edge. This paper shows the performance of the indexable insert with built-in micro thermocouples developed. The thickness of each element of the micro thermocouple is approximately 15 μm. The result of unsteady heat conduction analysis employing FEM shows that the temperature difference by installing the micro thermocouples is less than 10 K or 1.2 %. The temperature measurement experiments by cutting of aluminum alloy were carried out by changing the cutting speed. The results provided the evidence that the temperature distribution at the tool-chip interface can be grasped with the indexable insert with built-in micro thermocouples developed.
30
Rosman N., Andi. "Perancangan Termokopel Berbahan Besi (Fe) dan Tembaga (Cu) Untuk Sensor Temperatur." Indonesian Journal of Fundamental Sciences 4, no. 2 (October 1, 2018): 120. http://dx.doi.org/10.26858/ijfs.v4i2.7640.
Full textAbstract:
The design of iron (Fe) and Copper (Cu) thermocouples has been carried out for temperature sensors. The sensor will be made of two different types of materials namely iron and copper. The reference temperature used is 10C. The data collection procedure is first of all a thermocouple with a hot junction is tied together with a solder as a heat source. Besides that, it is also tied to a factory thermocouple that functions as a calibrator. Then the other end of the thermocouple (cold junction) will be inserted into a container containing ice cubes. Then the ports for each thermocouple will be connected to a multimeter, each of which is used to measure temperature (0C) and voltage (mV). From the results of observations and analyzes, it was found that for iron and copper thermocouples had the following characteristics: Seebeck coefficient was 0.001, the mean temperature rises and falls respectively (106.17 ± 0.82) 0C and (118.67 ± 0.90) 0C. The sensitivity of the thermocouple is 0.5 mV / 0C with linearity of 0.9.
31
Lundström, Hans, and Magnus Mattsson. "Modified Thermocouple Sensor and External Reference Junction Enhance Accuracy in Indoor Air Temperature Measurements." Sensors 21, no. 19 (October 1, 2021): 6577. http://dx.doi.org/10.3390/s21196577.
Full textAbstract:
Indoor air temperature belongs to the most important climatic variables in indoor climate research, affecting thermal comfort, energy balance, and air movement in buildings. This paper focuses on measurement errors when using thermocouples in indoor temperature measurements, with special attention on measurements of air temperature. We briefly discuss errors in thermocouple measurements, noting that, for temperatures restricted to indoor temperature ranges, a thermocouple Type T performs much better than stated in “standards”. When thermocouples are described in the literature, industrial applications are primarily considered, involving temperatures up to several hundred degrees and with moderate demands on accuracy. In indoor applications, the temperature difference between the measuring and the reference junction is often only a few degrees. Thus, the error contribution from the thermocouple itself is almost immeasurable, while the dominant error source is in the internal reference temperature compensation in the measuring instrument. It was shown that using an external reference junction can decrease the measurement error substantially (i.e., down to a few hundredths of a degree) in room temperature measurements. One example of how such a device may be assembled is provided. A special application of room temperature measurements involves measuring indoor air temperature. Here, errors, due to radiation influence on the sensor from surrounding surfaces, were surprisingly high. The means to estimate the radiative influence on typical thermocouples are presented, along with suggestions for modification of thermocouple sensors to lower the radiation impact and thereby improve the measurement accuracy.
32
Harashita, Junichi, Yuji Tomoda, and Jun Shinozuka. "Development of a Cutting Tool with Micro Built-In Thermocouples - Characteristic of the Micro Cu/Ni Thermocouples Fabricated by Electroless Plating and Electro Plating." Key Engineering Materials 523-524 (November 2012): 815–20. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.815.
Full textAbstract:
This study has devised a tool insert with micro built-in thermocouples in order to establish a cutting-temperature measuring method for practical use. This tool insert possesses seven pairs of micro Cu/Ni film thermocouple near the cutting edge on the rake face. In this study, Cu film and Ni film were deposited in the micro grooves corresponding to a circuit pattern of the micro thermocouple by means of electroless plating and electroplating. This paper shows the results of the investigation concerning the electrical properties of the micro Cu/Ni film thermocouples. The influence of the current density in electroplating on the electrical resistivity of the films was examined. The characteristic of the Seebeck property of the micro Cu/Ni film thermocouple was investigated in a temperature difference of up to 600 K with a heating apparatus developed. The Seebeck coefficient of the micro Cu/Ni film thermocouple was smaller by 28 % than that of a Cu/Ni wire thermocouple. The result implies that the degradation in the Seebeck property of the micro Cu/Ni film thermocouple derives from an existence of an impurity between Cu film and Ni film in the hot junction.
33
Mohammed, Hussein, Hanim Salleh, and Mohd Yusoff. "The transient response for different types of erodable surface thermocouples using finite element analysis." Thermal Science 11, no. 4 (2007): 49–64. http://dx.doi.org/10.2298/tsci0704049m.
Full textAbstract:
The transient response of erodable surface thermocouples has been numerically assessed by using a two dimensional finite element analysis. Four types of base metal erodable surface thermocouples have been examined in this study, included type-K (alumel-chromel), type-E (chromel-constantan), type-T (copper-constantan), and type-J (iron-constantan) with 50 mm thick- ness for each. The practical importance of these types of thermocouples is to be used in internal combustion engine studies and aerodynamics experiments. The step heat flux was applied at the surface of the thermocouple model. The heat flux from the measurements of the surface temperature can be commonly identified by assuming that the heat transfer within these devices is one-dimensional. The surface temperature histories at different positions along the thermocouple are presented. The normalized surface temperature histories at the center of the thermocouple for different types at different response time are also depicted. The thermocouple response to different heat flux variations were considered by using a square heat flux with 2 ms width, a sinusoidal surface heat flux variation width 10 ms period and repeated heat flux variation with 2 ms width. The present results demonstrate that the two dimensional transient heat conduction effects have a significant influence on the surface temperature history measurements made with these devices. It was observed that the surface temperature history and the transient response for thermocouple type-E are higher than that for other types due to the thermal properties of this thermocouple. It was concluded that the thermal properties of the surrounding material do have an impact, but the properties of the thermocouple and the insulation materials also make an important contribution to the net response.
34
Atroshenko, Yuliana K., Irina P. Ozerova, and Pavel A. Strizhak. "Predictive Modelling of the Warming up Times for Thermoelectric Converters." Advanced Materials Research 1040 (September 2014): 965–68. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.965.
Full textAbstract:
In the present article the question of simulation of nonstationary process of heat transport in a sensitive element of the thermoelectric transformer with an uninsulated seal is considered. The model allows defining and comparing the heating time of a thermocouple junction up to the given temperature for different types of thermocouples. In this article the values obtained by means of modelling the heat time of different thermocouples and also a temperature field in a sensitive element of the thermoelectric transformer are given.
35
Kalyak, A. A., S. A. Kazantsev, V. M. Gruznov, and I. I. Zasypkina. "Instrumentation complex for measuring the thermophysical properties of rocks in natural occurrence temperature conditions." Journal of Physics: Conference Series 2388, no. 1 (December 1, 2022): 012137. http://dx.doi.org/10.1088/1742-6596/2388/1/012137.
Full textAbstract:
Abstract A schematic diagram and an operation algorithm of an instrumentation complex for measuring the thermal conductivity and thermal diffusivity of rocks by the non-stationary method of a linear source under natural occurrence temperature conditions up to 200 °C are proposed. Thermocouples are used to measure the temperature of the probes. The complex contains two linear (needle) probes, which are placed in a rock sample at a certain distance r from each other. One probe, containing a linear heater and a thermocouple, radiates heat, the other one, containing a thermocouple, is a measuring probe. The cold junction temperature of thermocouples is measured by a semiconductor sensor. To calculate the voltage of the cold junction from the value of its temperature, a direct conversion of thermoEMF by a power polynomial is used. To calculate the temperature of the hot junction of the probe, an inverse transformation by a power polynomial of the voltage values of the hot junction of thermocouples into temperature was applied. In direct and inverse transformations, the degree of polynomials is 10. To reduce the temperature measurement error, digital filtering of signals from thermocouples was used. A digital-to-analogue converter is included in the heater circuit of the radiating probe for flexible heating control. The results of measuring the thermal conductivity and thermal diffusivity of dry and wet sand samples are consistent with the literature data on the temperature dependence.
36
Palmer, A. J., R. S. Skifton, M. Scervini, D. C. Haggard, and W. D. Swank. "Performance of Custom-Made Very High Temperature Thermocouples in the Advanced Gas Reactor Experiment AGR-5/6/7 during Irradiation in the Advanced Test Reactor." EPJ Web of Conferences 225 (2020): 04010. http://dx.doi.org/10.1051/epjconf/202022504010.
Full textAbstract:
The Advanced Gas Reactor-5/6/7 (AGR-5/6/7) experiment is the fourth and final experiment in the AGR experiment series and will serve as the formal fuel qualification test for the TRISO fuels under development by the U.S. Department of Energy. Certain locations in this experiment reach temperatures higher than any of the previous AGR tests, up to 1500°C. Such extreme temperatures create unique challenges for thermocouple-based temperature measurements. High-temperature platinum-rhodium thermocouples (Types S, R, and B)and tungsten-rhenium thermocouples (Type C) suffer rapiddecalibration due to transmutation of the thermoelements fromneutron absorption. For lower temperature applications, previousexperience with Type K thermocouples in nuclear reactors haveshown that they are affected by neutron irradiation only to alimited extent. Similarly, Type N thermocouples, which are morestable than Type K at high temperatures, are only slightly affectedby neutron fluence. Until recently, the use of these nickel-basedthermocouples was limited when the temperature exceeds 1050°Cdue to drift related to phenomena other than nuclear irradiation.Recognizing the limitations of existing thermometery to measuresuch high temperatures, the sponsor of the AGR-5/6/7 experimentsupported a development and testing program for thermocouplescapable of low drift operation at temperatures above 1100°C. High Temperature Irradiation Resistant Thermocouples (HTIR-TCs)based on molybdenum/niobium thermoelements have been underdevelopment at Idaho National Laboratory (INL) since circa 2004. A step change in accuracy and long-term stability of thisthermocouple type has been achieved as part of the AGR-5/6/7thermometry development program. Additionally, long-termtesting (9000+ hrs) at 1250°C of the Type N thermocouplesutilizing a customized sheath developed at the University ofCambridge has been completed with low drift results. Both theimproved HTIR and the Cambridge Type N thermocouple typeshave been incorporated into the AGR-5/6/7 test, which beganirradiation in February 2018 in INL’s Advanced
37
Hardianto, Hardianto, Benny Malengier, Gilbert De Mey, Lieva Van Langenhove, and Carla Hertleer. "Textile yarn thermocouples for use in fabrics." Journal of Engineered Fibers and Fabrics 14 (January 2019): 155892501983609. http://dx.doi.org/10.1177/1558925019836092.
Full textAbstract:
Thermocouples are mainly used for accurate temperature measurements, but they can also be used for the generation of electric energy at low voltage and low power. If inserted into wearable garments, these thermocouples can be used to supply the electric energy required by portable electronic devices. The heat from the human body gives rise to a temperature gradient which can be converted into electric power. In this article, we study the possibility to create a thermocouple and thermopile from pure conductive textile yarns. Among the materials tested, nickel-coated carbon fiber in combination with stainless steel yarn, polypyrrole-coated carbon fiber, or carbon fiber has good potential to be a textile-based thermocouple. We also successfully made a 10-pair carbon fiber–nickel-coated carbon fiber junction thermopile from a single nickel-coated carbon fiber yarn by removing the nickel selectively through etching process.
38
Cherkez, R. G., E. Pozhar, and А. Gykova. "Influence of Channel Diameter on the Efficiency of Permeable Thermoelements From Bi-Te-Se-Sb Materials." Фізика і хімія твердого тіла 20, no. 4 (December 15, 2019): 467–71. http://dx.doi.org/10.15330/pcss.20.4.467-471.
Full textAbstract:
The results of studies of permeable thermoelements are presented. The physical model, method of calculation and design of a permeable thermocouple in which the fluid is pumped through the branches of the semiconductor material are described. For materials based on Bi-Te-Se-Sb, the influence of structural parameters (channel diameter and number, branch height and number of segments) in optimal conditions of thermoelement efficiency on energy characteristics is calculated. The features of methods of solving problems in 3-D and 1-D cases for different models of permeable thermocouples are described. 3-D simulation of the generator thermocouple based on COMSOL Multiphysics was used for the calculations. On the basis of computer-aided design, optimal values of such parameters are calculated, which allow to establish the necessary material science requirements for the creation of thermocouple and indicate the possibility of increasing the efficiency of thermoelectric energy conversion by 1.2 - 1.5 times compared to traditional thermocouples.
39
Ellappan, R., J. Manoj Karan, and K. Nandu Narayanan. "Generation of Electricity from the Waste Heat of an IC Engine Using Thermo Electric Device." Applied Mechanics and Materials 813-814 (November 2015): 841–45. http://dx.doi.org/10.4028/www.scientific.net/amm.813-814.841.
Full textAbstract:
Electricity is very vital in our day to day life. The motive of our journal is to generate electricity from the from the exhaust gases of an internal combustion engine by the principle of Seebeck effect.Exhaust gases from an automobile bring out the excess heat generated which would be very high.The idea is to convert this exhaust heat to another form of energy i.e., electricity with the help of thermoelectric devices like thermocouples, thermopiles, Peltier device. The voltage generated by the thermocouple is very small and many thermocouples are required to make a practical thermoelectric generator. If a loop is made from wires using two dissimilar metals, a voltage will appear between the junctions of the wires if one junction is hotter than the other. Such a loop made with dissimilar metals is known as a thermocouple and the phenomenon is named the Seebeck effect. A semi conductor thermocouple device named Peltier device is used to convert the exhaust heat generated from an automobile into electricity.
40
Zeng, Qi Yong, Xiao Feng Zheng, Gao Hui Zhang, and Le Chen. "Development of Cutting Tools with Built-in Thin Film Thermocouple for Monitoring Machining Temperature." Advanced Materials Research 189-193 (February 2011): 3170–74. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.3170.
Full textAbstract:
Temperature plays a vital role in the machining industry today. NiCr/NiSi thin-film thermocouples have been deposited on the rake face of polycrystalline cubic boron nitride (PCBN) tools by magnetron sputtering. The typical deposition conditions are summarized. Static and dynamic calibrations of the NiCr/NiSi thin-film thermocouples are presented. The Seebeck coefficient of the TFTC is 37.3 μV/°C. The response time is about 3.9 ms. The testing results indicate that the developed NiCr/NiSi thin-film thermocouple sensors perform excellently when machining A3 steel in situ.
41
Zhao, Chenyang, and Zhijie Zhang. "Dynamic Error Correction of Filament Thermocouples with Different Structures of Junction based on Inverse Filtering Method." Micromachines 11, no. 1 (December 30, 2019): 44. http://dx.doi.org/10.3390/mi11010044.
Full textAbstract:
Since filament thermocouple is limited by its junction structure and dynamic characteristics, the actual heat conduction process cannot be reproduced during the transient thermal shock. In order to solve this problem, we established a thermocouple dynamic calibration system with laser pulse as excitation source to transform the problem of the restoring excitation source acting on the surface temperature of thermocouple junction into the problem of solving the one-dimensional (1D) inverse heat conduction process, proposed a two-layer domain filtering kernel regularization method for double conductors of thermocouple, analyzed the factors causing unstable two-layer domain solution, and solved the regular solution of two-layer domain by the filtering kernel regularization strategy. By laser narrow pulse calibration experiment, we obtained experimental samples of filament thermocouples with two kinds of junction structures, butt-welded and ball-welded; established error estimation criterion; and obtained the optimal filtering kernel parameters by the proposed regularization strategy, respectively. The regular solutions solved for different thermocouples were very close to the exact solution under the optimal strategy, indicating that the proposed regularization method can effectively approach the actual surface temperature of the thermocouple junction.
42
Tillmann, Wolfgang, David Kokalj, Dominic Stangier, Volker Schöppner, and Hatice Malatyali. "Combining Thermal Spraying and Magnetron Sputtering for the Development of Ni/Ni-20Cr Thin Film Thermocouples for Plastic Flat Film Extrusion Processes." Coatings 9, no. 10 (September 24, 2019): 603. http://dx.doi.org/10.3390/coatings9100603.
Full textAbstract:
In the digitalization of production, temperature determination is playing an increasingly important role. Thermal spraying and magnetron sputtering were combined for the development of Ni/Ni-20Cr thin film thermocouples for plastic flat film extrusion processes. On the thermally sprayed insulation layer, AlN and BCN thin films were deposited and analyzed regarding their structural properties and the interaction between the plastic melt and the surfaces using Ball-on-Disc experiments and High-Pressure Capillary Rheometer. A modular tool, containing the deposited Ni/Ni-20Cr thin film thermocouple, was developed and analyzed in a real flat film extrusion process. When calibrating the thin film thermocouple, an accurate temperature determination of the flowing melt was achieved. Industrial type K sensors were used as reference. In addition, PP foils were produced without affecting the surface quality by using thin film thermocouples.
43
ISKANDAROV, NABI, ELMIN BAGISHOV, and ELCHIN ISGANDARZADA. "EFFECT OF SURFACE SENSOR AND EXTERNAL REFERENCE NODE ON PROCESS TEMPERATURE MEASUREMENT ACCURACY." Computational Nanotechnology 9, no. 1 (March 28, 2022): 145–53. http://dx.doi.org/10.33693/2313-223x-2022-9-1-145-153.
Full textAbstract:
As we know, one of the most important and important issues in the implementation of technological processes is the implementation of accurate and correct temperature measurements. During the research, attention was paid to the measurement errors in temperature measurements of technological processes using thermocouples and methods of minimizing those errors. In addition, errors in thermocouple temperature measurements were briefly discussed, and for temperatures limited to a certain range, the T-type thermocouple achieved several times less error than the allowable error specified in the normative documents. It is known that when describing thermocouples in the technical literature, first of all, industrial devices with high temperature coefficient and medium class accuracy are considered. Also, as we know, in domestic applications, the temperature difference between the measurement and the reference node varies mainly within the minimum threshold range. Therefore, if the main source of error is the internal reference temperature compensation in the measuring instrument, it is almost impossible to determine the proportion of errors due to the thermocouple itself. The study found that the measurement error can be significantly reduced when determining the temperature of technological processes using an external reference node. At the same time, since the special application of temperature measurements of technological processes covers the measurement of indoor and outdoor temperatures, the errors due to the effect of radiation on the sensor from the surrounding surfaces are many times higher than the allowable error. For this reason, tools have been proposed to assess the radiation effects on typical thermocouples, along with proposals for modification of thermocouple sensors to reduce the potential radiation exposure and thus increase measurement accuracy.
44
Pombo, Inigo, Jose Antonio Sánchez, N. Ortega, B. Izquierdo, and S. Plaza. "Characterization of the Response of Embedded Thermocouples in Grinding." Advanced Materials Research 325 (August 2011): 12–18. http://dx.doi.org/10.4028/www.scientific.net/amr.325.12.
Full textAbstract:
Temperature measurement in grinding has been a widely analyzed field in the study of the process. Temperatures in grinding are too difficult to measure due to the high gradients in the ground workpiece. A lot of different methods have been employed by many researches in the last years. In this paper the use of thermocouples is analyzed attending to the mathematical characterization of their response. It will be shown that correct modeling of the thermocouple’s response permits the avoidance of the problem of thermal inertia, making thus possible the use commercial thermocouples for temperature measurement in grinding.
45
Nedic, Bogdan, and Milan Eric. "Cutting temperature measurement and material machinability." Thermal Science 18, suppl.1 (2014): 259–68. http://dx.doi.org/10.2298/tsci120719003n.
Full textAbstract:
Cutting temperature is very important parameter of cutting process. Around 90% of heat generated during cutting process is then away by sawdust, and the rest is transferred to the tool and workpiece. In this research cutting temperature was measured with artificial thermocouples and question of investigation of metal machinability from aspect of cutting temperature was analyzed. For investigation of material machinability during turning artificial thermocouple was placed just below the cutting top of insert, and for drilling thermocouples were placed through screw holes on the face surface. In this way was obtained simple, reliable, economic and accurate method for investigation of cutting machinability.
46
Jun, Su, and Orest Kochan. "Investigations of Thermocouple Drift Irregularity Impact on Error of their Inhomogeneity Correction." Measurement Science Review 14, no. 1 (February 1, 2014): 29–34. http://dx.doi.org/10.2478/msr-2014-0005.
Full textAbstract:
Abstract The article examines: (i) the reasons of error due to thermoelectric inhomogeneity of electrodes of thermocouples acquired during prolonged use; (ii) the neural network method of error correction based on a generalization of verification results in several temperature fields; (iii) the method of investigating the impact of changing the speed of the conversion characteristic drift of thermocouple on error correction; (iv) results of this investigation. It is shown that residual error for type K thermocouples at the 5 % level of significance does not exceed μ±0.46 oС and one at the 10 % level of significance does not exceed ±0.25 °С
47
Tyree, M. T., and T. R. Wilmot. "Errors in the calculation of evaporation and leaf conductance in steady-state porometry: the importance of accurate measurement of leaf temperature." Canadian Journal of Forest Research 20, no. 7 (July 1, 1990): 1031–35. http://dx.doi.org/10.1139/x90-137.
Full textAbstract:
Leaf temperatures of sugar maple leaves (Acersaccharum Marsh.) were measured over three growth seasons using in situ copper–constantan thermocouples with wire and junction diameters of 70 and 130 μm, respectively. These thermocouples were coated with a thin layer of adhesive and attached to the abaxial leaf surface over a length of 4 to 5 cm of wire. On sunny days leaf temperatures usually rose 5 to 15 °C above the air temperature. When leaf conductances and evaporative flux were measured with a Li-Cor steady-state porometer under the same conditions, similar leaf temperatures were rarely measured by the Li-Cor leaf thermocouple. We argue that the in situ thermocouple is more likely to measure the actual leaf temperature than the Li-Cor thermocouple. Consequently, the values for leaf conductance and evaporative flux computed by the Li-Cor microprocessor can be wrong by as much as a factor of 2. Errors of similar magnitude may apply to other published measurements for forest species but are not as large in many crop species.
48
Kuppu Rao, V., and M. F. Bardon. "A note on the measurement of temperature in reciprocating engines using thermocouples." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 223, no. 9 (September 1, 2009): 1187–92. http://dx.doi.org/10.1243/09544070jauto1158.
Full textAbstract:
This paper presents a theoretical analysis of the response of a thermocouple placed in a reciprocating engine. The manner in which the temperatures recorded by the thermocouple lag behind and are attenuated from the fluctuating fluid temperatures because of thermal inertia of the thermocouple is analysed. A method is suggested for computing the true fluid temperatures from the measured temperatures in an engine under both motoring and operating conditions. This compensation technique allows the use of larger, more robust thermocouples without losing the rapid time response of very small thermocouple wires.
49
Beiranvand, Behrokh, Alexander S. Sobolev, and Anton V. Kudryashov. "Composite right/left-handed transmission line with array of thermocouples for generating terahertz radiation." European Physical Journal Applied Physics 92, no. 2 (November 2020): 20502. http://dx.doi.org/10.1051/epjap/2020200208.
Full textAbstract:
We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.
50
Seibold, Florian, Andreas Schwab, Victor Dubois, Rico Poser, Bernhard Weigand, and Jens von Wolfersdorf. "Conduction and Inertia Correction for Transient Thermocouple Measurements. Part I: Analytical and Numerical Modelling." E3S Web of Conferences 345 (2022): 01002. http://dx.doi.org/10.1051/e3sconf/202234501002.
Full textAbstract:
Two-wire thermocouples are often used for temperature measurements. Under transient conditions, measurement errors can occur due to capacitive inertia and heat conduction along the stem of the thermocouples. The present study presents a correction of these thermocouple measurement errors caused by transient inertia and conductive effects using a simplified analytical approach and its numerical solution. Based on an energy balance the mathematical modelling is derived and analytically solved for specific boundary conditions. Further, numerical solutions have been implemented with different model complexities. Thereby the models show the significance of the necessary correction as well as the good agreement with theoretical considerations. A corresponding experimental validation is given in Part II.