To see the other types of publications on this topic, follow the link: Thermocouple.
Journal articles on the topic 'Thermocouple'
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 'Thermocouple.'
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
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.
2
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.
3
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.
4
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.
5
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.
6
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.
7
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.
8
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.
9
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.
10
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.
11
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.
12
Wang, Qifu, Meng Gao, Lunjia Zhang, Zhongshan Deng, and Lin Gui. "A Handy Flexible Micro-Thermocouple Using Low-Melting-Point Metal Alloys." Sensors 19, no. 2 (January 14, 2019): 314. http://dx.doi.org/10.3390/s19020314.
Full textAbstract:
A handy, flexible micro-thermocouple using low-melting-point metal alloys is proposed in this paper. The thermocouple has the advantages of simple fabrication and convenient integration. Bismuth/gallium-based mixed alloys are used as thermocouple materials. To precisely inject the metal alloys to the location of the sensing area, a micro-polydimethylsiloxane post is designed within the sensing area to prevent outflow of the metal alloy to another thermocouple pole during the metal-alloy injection. Experimental results showed that the Seebeck coefficient of this thermocouple reached −10.54 μV/K, which was much higher than the previously reported 0.1 μV/K. The thermocouple was also be bent at 90° more than 200 times without any damage when the mass ratio of the bismuth-based alloy was <60% in the metal-alloy mixture. This technology mitigated the difficulty of depositing traditional thin–film thermocouples on soft substrates. Therefore, the thermocouple demonstrated its potential for use in microfluidic chips, which are usually flexible devices.
13
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.
14
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.
15
Offenzeller, Christina, Marcel Knoll, Bernhard Jakoby, and Wolfgang Hilber. "Fully Screen Printed Carbon Black-Only Thermocouple and the Corresponding Seebeck Coefficients." Proceedings 2, no. 13 (November 30, 2018): 802. http://dx.doi.org/10.3390/proceedings2130802.
Full textAbstract:
This work presents a thermocouple that is fully screen printed and consists exclusively of carbon black conductors. Two different carbon black inks were printed to form a thermocouple, which has been characterized regarding its output voltage. For reference, each of the carbon black inks was used in combination with gold to form two further thermocouples. These have also been characterized and the output voltage used to predict the output of the associated thermocouple consisting of pure carbon black conductors. The results have been compared with the measurement results and show that the output of the pure carbon black thermocouple is roughly 10% lower than expected.
16
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.
17
Filippovich, Р. A., and S. A. Gurova. "Method of reducing the inertia of a thermocouple cable CTMS based on a cable of variable cross-section to improve reliability in aviation and rocket and space technology." Informacionno-technologicheskij vestnik, no. 2 (July 30, 2019): 65–71. http://dx.doi.org/10.21499/2409-1650-2019-2-65-71.
Full textAbstract:
The method of reducing the inertia of the thermocouple cable ctms based on the use of a cable of variable cross-section is considered. The comparative analysis of time of establishment of thermal equilibrium of a thermocouple cable with variable cross-section and without it is given. The time before the establishment of thermal equilibrium is considered. From a technological point of view, the use of thermocouples based on chromel-alumel is justified. The parameters of inertia of a thermocouple cable of variable cross-section are given.
18
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.
19
Wu, Shuo, Fang Ye, Hang Guo, and Chong Fang Ma. "Static and Dynamic Response of a Cu-Ni Thin Film Heat Flux Sensor." Advanced Materials Research 960-961 (June 2014): 304–7. http://dx.doi.org/10.4028/www.scientific.net/amr.960-961.304.
Full textAbstract:
A Cu-Ni thin film heat flux sensor had been fabricated on a 0.05mm thick polyimide film substrate by vacuum coating technology. The overall dimension of the sensor was 8 mm long and 4 mm wide. A thermopile and a thermocouple were arranged on the substrate to measure both heat flux and surface temperature. The thermopile had 18 thermocouple junctions which formed 9 pairs of differential thermocouples and were covered by two different thickness of thermal resistance layers. This research carried out static and dynamic tests of the thin film heat flux sensor. Seebeck coefficient of thermocouple is 19.3761μV/(°C). Sensitivity of the thermopile is 0.010121μV/(W/m2). Steady-state tests of the thermopile and the thermocouple were taken separately. Time constant of the thermocouple is about 0.26s, which is faster than the thermopile of 1.57s.
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
Lin, Qi Feng, and Shu Yong Mou. "Research of Low Noise Analog Measurement on High Temperature Thermocouple Based on dsPIC33." Advanced Materials Research 816-817 (September 2013): 938–42. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.938.
Full textAbstract:
Since thermocouple has an intrinsic disadvantage that its signal is very weak, many problems usually appear such as large noise and low temperature resolution when thermocouples are being used. Aiming this defect on thermocouple measurement, this paper proposes a solution of analog circuit design that provides the character of low noise and high SNR. This paper discusses the analog circuit design and calculation based on the S-type thermocouple which is often used for a very wide temperature range. This designed module can be applied to measurement instruments.
22
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.
23
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.
24
Wang, Yufang, Jian Zhao, and Ruijia Zhao. "Shape Parameterization Optimization of Thermocouples Used in Aeroengines." Aerospace 10, no. 2 (February 20, 2023): 202. http://dx.doi.org/10.3390/aerospace10020202.
Full textAbstract:
Aiming at the problem that thermocouples used in different parts of aeroengines need a lot of repeated design work in application and the high precision requirements as special test sensors, a parameterized optimization method for a thermocouple shape combined with a numerical simulation method is proposed. The performance of a dual-screen thermocouple (DST), single-screen thermocouple (SST), and no-screen thermocouple (NST) is tested by a numerical simulation method, and is represented by the velocity error σV and the restitution coefficient r. The dual-screen thermocouple (DST) is the best one, and it is selected as the object to parametric optimization, and the parametric optimization methods based on it, geometrically modeled parametrically, adaptive mesh generation and parametric numerical simulation, are proposed. For a dual-screen thermocouple (DST), eight design structural parameters and four environment parameters are suggested for geometrically modeled parametrically and parametric numerical simulation, respectively. The dichotomy method is used to find the optimal length of the screen L, which is considered the most relevant parameter for thermocouple performance. It can be found that the length of the screen L corresponding to the optimal restitution coefficient r ranges from 56.25 to 62.5 mm.
25
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.
26
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.
27
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.
28
Wan, Yi, Zhi Tao Tang, Zhan Qiang Liu, and Xing Ai. "The Assessment of Cutting Temperature Measurements in High-Speed Machining." Materials Science Forum 471-472 (December 2004): 162–66. http://dx.doi.org/10.4028/www.scientific.net/msf.471-472.162.
Full textAbstract:
High-speed machining has received important interest because it leads to an increase of productivity and a better workpiece surface quality. However, the tool wear increases dramatically in high-speed machining (HSM) operations due to the high cutting temperature at the tool-workpiece interface and chip-tool interface. Cutting temperature and its gradient play an important role in tool life and machined part accuracy. This paper reviews different methods of the measurements of cutting temperature, which include: (1) thermocouples---tool-work thermocouple, embedded thermocouple, combination thermocouple and compensation thermocouple (2) optical infrared pyrometer, (3) infra-red photography, (4) thermal paints, (5) microstructure or microhardness observation. Each method has its advantages and limitations. The fundamental principles and application fields of each measurement method are presented, which is useful for the selection of the measurement methods for high-speed cutting temperature.
29
CHEN, Y. Z., H. C. JIANG, W. L. ZHANG, X. Z. LIU, and S. W. JIANG. "FILM THICKNESS INFLUENCES ON THE THERMOELECTRIC PROPERTIES OF NiCr/NiSi THIN FILM THERMOCOUPLES." Modern Physics Letters B 27, no. 14 (May 16, 2013): 1350103. http://dx.doi.org/10.1142/s0217984913501030.
Full textAbstract:
NiCr / NiSi thin film thermocouples (TFTCs) with a multi-layer structure were fabricated on Ni -based superalloy substrates (95 mm × 35 mm × 2 mm) by magnetron sputtering and electron beam evaporation. The five-layer structure is composed of NiCrAlY buffer layer (2 μm), thermally grown Al 2 O 3 bond layer (200 nm), Al 2 O 3 insulating layer (10 μm), NiCr / NiSi TFTCs (1 μm), and Al 2 O 3 protective layer (500 nm). Influences of thermocouple layer thickness on thermoelectric properties were investigated. Seebeck coefficient of the samples with the increase in thermocouple layer thickness from 0.5 μm to 1 μm increased from 27.8 μV/°C to 33.8 μV/°C, but exhibited almost no change with further increase in thermocouple layer thickness from 1 μm to 2 μm. Dependence on temperature of the thermal electromotive force of the samples almost followed standard thermocouple characteristic curves when the thickness of the thermocouple layer was 1 μm and 2 μm. Sensitive coefficient K of the samples increased greatly with the increase in thickness of the thermocouple layer from 0.5 μm to 1 μm, but decreased insignificantly with the increase in thermocouple layer thickness from 1 μm to 2 μm, and continuously decreased with the increase in temperature. The sensitive coefficient and the stability of NiCr / NiSi TFTCs were both improved after annealing at 600°C.
30
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.
31
Kanesalingam, Jeevan, See Fung Lee, and Hock Guan Ho. "Study of Temperature Measurement Accuracy by Using Different Mounting Adhesives." Journal of Engineering Technology and Applied Physics 2, no. 2 (December 15, 2020): 24–27. http://dx.doi.org/10.33093/jetap.2020.2.2.4.
Full textAbstract:
Thermal compounds are adhesive used to improve heat conduction between two surfaces. It can be used to secure a thermocouple to a surface which the temperature is being measured. This paper studies the temperature accuracy when using different types of thermal adhesives to secure thermocouples to a metal surface. An aluminum block attached to heater resistors was heated up by supplying varying power levels to create different temperatures. The measured temperature is compared to a reference thermocouple in the aluminum block to check the accuracy of each thermocouple when it is secured with different adhesives. It was found using the Loctite 3873 to secure a thermocouple to a metal surface will produce the most accurate temperature reading with an error below 2.6°C. This enables researchers to use the appropriate adhesive to obtain the most accurate results and also to know what are the errors contributed by different adhesives.
32
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.
33
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.
34
Deng, Jinjun, Linwei Zhang, Liuan Hui, Xinhang Jin, and Binghe Ma. "Indium Tin Oxide Thin-Film Thermocouple Probe Based on Sapphire Microrod." Sensors 20, no. 5 (February 27, 2020): 1289. http://dx.doi.org/10.3390/s20051289.
Full textAbstract:
Indium tin oxide (ITO) thin-film thermocouples monitor the temperature of hot section components in gas turbines. As an in situ measuring technology, the main challenge of a thin-film thermocouple is its installation on complex geometric surfaces. In this study, an ITO thin-film thermocouple probe based on a sapphire microrod was used to access narrow areas. The performance of the probe, i.e., the thermoelectricity and stability, was analyzed. This novel sensor resolves the installation difficulties of thin-film devices.
35
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.
36
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.
37
Sharma, P., N. Murali, and T. Jayakumar. "Effect of thermocouple time constant on sensing of temperature fluctuations in a fast reactor subassembly." Journal of Sensors and Sensor Systems 3, no. 1 (February 20, 2014): 55–60. http://dx.doi.org/10.5194/jsss-3-55-2014.
Full textAbstract:
Abstract. Knowledge of temperature fluctuations in fast reactor subassembly is very important from a safety point of view. The time constant of thermocouples which are used for measuring coolant temperature in a fast reactor varies owing to various factors. Hence, it becomes necessary to investigate the effect of change in the time constant on sensed fluctuations. This paper investigates the dependence of temperature fluctuations on thermocouple time constants. A Scilab model consisting of source temperature profile, second-order thermocouple and histogram calculation is designed. Simulation is performed for various levels of fluctuations, fixed and variable thermocouple time constants. Kurtosis for each condition is calculated with the help of a histogram. It is found that the effect of true source fluctuations on sensor output is very large compared to that of a similar percentage of time-constant variations. Hence in systems like fast reactors, where the degree of source fluctuations (fluid enthalpy) is large in comparison to that of time-constant variations, the overall effect can be considered with great confidence to be the outcome of coolant temperature rather than thermocouple time-constant variations.
38
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.
39
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.
40
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.
41
Samboruk, Anatoliy R., Aleksandr P. Amosov, Elena A. Kuznets, Antonina A. Kuzina, and Yuri M. Markov. "Development of Technology of Nicrosil and Nisil Thermocouple Materials Using Extrusion of Metal Powders." Key Engineering Materials 746 (July 2017): 201–6. http://dx.doi.org/10.4028/www.scientific.net/kem.746.201.
Full textAbstract:
Nicrosil-nisil (NiCrSi-NiSi) thermocouples (Type N) have a high thermal EMF stability, radiation resistance, resistance to oxidation of the thermocouple wires and can be used as a universal means of measuring temperatures up to 1300 °C. However, when the traditional metallurgical method is used for the production of rod and wire materials of nicrosil and nisil from ingots of metals, it is difficult to ensure the homogeneity of the ingots and materials of the thermocouple. It is known that powder metallurgy methods can provide a greater homogeneity of the material compared to casting technology. The aim of this work was to study the possibility of using powder technology for the fabrication of rods of nicrosil and nisil thermocouple materials by extrusion and sintering of powders of source metals. Reduction in size and mixing of the raw powder components in a planetary ball mill was investigated. The regularities of pressing the prepared mixtures and microstructure of materials sintered from them were determined. Samples of nicrosil and nisil thermocouple materials in the form of cylindrical rods with a diameter of about 5 mm and a length of 200 mm with an uniform microstructure were also fabricated by extrusion of prepared mixtures followed by sintering. Experimentally determined specific differential thermal EMF of the thermocouple made from the sintered rods coincided with the theoretical value.
42
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.
43
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.
44
Cui, Yun Xian, Yang Qi, Li Ming Guo, Qi Xiang Zhang, and Ying Jia. "The Design of Automatic System for the Calibration of Testing Temperature Cutter with Thin Film Thermocouple." Materials Science Forum 836-837 (January 2016): 552–61. http://dx.doi.org/10.4028/www.scientific.net/msf.836-837.552.
Full textAbstract:
In order to get an accurate online measurement for the transient cutting temperature in precision, in an ultra-precision cutting process,a temperature measuring device should be assessed whether it can obtain precise magnitude readings and variables of which are measured accurately. The just produced thin-film thermocouple used to measure tool cutting temperature must be correctly calibrated[3,4] , however traditional calibrating process problems rely on manual operation completely with lots of problems such as low efficiency, high labor intensity and large error. this paper proposes an automatic calibration system for thin-film thermocouple by using temperature measuring furnace, data acquisition card and computer-based software. The system makes an automatically and intelligently calibration process. By using a high-precision data acquisition card and precision amplifier circuit, eight thermocouples can be calibrated at the same time automatically which effectively shortens the calibration time and improves the accuracy. Use temperature metering furnace to control data acquisition. Secondary error from using standard thermocouple and other methods to collect the temperature metering furnace real-time temperature is eliminated. The system software modules consist of data reading, data processing, data display, database operation, data query and report generation module. The experimental results show that nonlinear fitting error is less than 0.6% within the temperature measurement range, which meets the requirement of the secondary precision of thermocouple error. This paper intends to provide a new calibration method for thermocouple temperature measurement tool development and production[7].
45
Król, Aleksander, Wolfram Jahn, Grzegorz Krajewski, Małgorzata Król, and Wojciech Węgrzyński. "A Study on the Reliability of Modeling of Thermocouple Response and Sprinkler Activation during Compartment Fires." Buildings 12, no. 1 (January 13, 2022): 77. http://dx.doi.org/10.3390/buildings12010077.
Full textAbstract:
Real and numerical fire experiments involve temperature measurements with thermocouples, and thus some considerations on numerical modeling of this process are presented and a new approach to thermocouple modeling is introduced. Using ANSYS Fluent software a well-recognized analytical thermocouple model was implemented in each cell of the computational domain, which allows for determination of thermocouple responses as a continuous field. Similarly, sprinklers are key elements of fire-protection systems. Sprinklers activation is one of the breakthrough moments during the course of a compartment fire. Therefore, assumptions on sprinkler activation time are of crucial importance when designing a fire safety system. Just as for thermocouple modeling, virtual sprinklers based on a commonly admitted response time index (RTI) model were placed in all cells. The proposed approach provides data on sprinklers activation or thermocouple response for the whole domain instead of retrieving data point by point only for predefined locations. In this study, experimental data available in the literature were used for the validation of the proposed approach. In addition, the results were compared with those obtained with the commonly used Fire Dynamic Simulator (FDS) software. The outcomes might be of a significant importance for practitioners, who deal with fire experiments and fire protection. Furthermore, some issues on accurate modeling of fire gases flow are discussed extensively. It was found that commonly applied k-ε and k-ω turbulence models might fail in the case of modeling of fire plumes in confined spaces.
46
Milecki, Andrzej, and Dominik Rybarczyk. "The Gas Fire Temperature Measurement for Detection of an Object’s Presence on Top of the Burner." Sensors 20, no. 7 (April 10, 2020): 2139. http://dx.doi.org/10.3390/s20072139.
Full textAbstract:
This article covers the topic of temperature measurement on top of a gas burner fire in order to recognize pot removal from a gas burner and subsequently, to cut off the gas supply. The possibility of applying a factory-mounted thermocouple was investigated with the assumption that its output signal could be used to detect the presence of a pot on a gas burner. However, the characteristic of such a thermocouple is not fully linear and as the research has shown that such a thermocouple would not fit enough for the assumed purpose, thus another sensor needs to be used. Therefore, in this paper, the linear thermocouple and IR diode are used. The best localizations of theses sensors were investigated in order to obtain a signal suitable for the pot presence recognition over the burner. These investigations are supported by the use of an infrared camera. In the investigations, the temperature changes also caused by casual air blast or caused by increasing and decreasing the valve opening are recorded and analyzed. Finally, the changes of the thermocouple’s signals are used as an input signal to propose an algorithm for pot absence recognition over the burner. The microprocessor-based circuit with a control unit for detection of the pot absence is designed, built and investigated.
47
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.
48
Hadi, Abdul-Sommed, Bryce E. Hill, and Mohammed Naziru Issahaq. "Performance Characteristics of Custom Thermocouples for Specialized Applications." Crystals 11, no. 4 (April 5, 2021): 377. http://dx.doi.org/10.3390/cryst11040377.
Full textAbstract:
This work reports the performance characteristics of custom thermocouples developed for use in elevated temperatures such as metal casting operations. The scope of this research is limited to thermocouples designed using pyrolytic graphite (PG) as the primary thermoelement in connection with aluminum, copper, steel, and tungsten. The Seebeck coefficients of the sensors were determined from experimental data after heating to ~500 °C. Cooling from ~500 °C to room temperature enabled us to compare the characteristic behaviors of the sensors from the obtained near-linear responses in the voltage-temperature plots. Tungsten being a refractory metal produced the highest sensitivity of the sensors. The sensitivity of the PG-tungsten thermocouple upon heating measured up to 26 μV/°C and a slightly lower value of 24.2 μV/°C was obtained upon cooling. Conversely, the PG-steel thermocouple rather produced the lowest Seebeck coefficients of 13.8 μV/°C during heating and 14.0 μV/°C for the cooling experiments though steel has a high melting temperature than most of the other thermoelements.
49
Jaremkiewicz, Magdalena. "Reduction of dynamic error in measurements of transient fluid temperature." Archives of Thermodynamics 32, no. 4 (December 1, 2011): 55–66. http://dx.doi.org/10.2478/v10173-011-0031-3.
Full textAbstract:
Reduction of dynamic error in measurements of transient fluid temperatureUnder steady-state conditions when fluid temperature is constant, temperature measurement can be accomplished with high degree of accuracy owing to the absence of damping and time lag. However, when fluid temperature varies rapidly, for example, during start-up, appreciable differences occur between the actual and measured fluid temperature. These differences occur because it takes time for heat to transfer through the heavy thermometer pocket to the thermocouple. In this paper, a method for determinig transient fluid temperature based on the first-order thermometer model is presented. Fluid temperature is determined using a thermometer, which is suddenly immersed into boiling water. Next, the time constant is defined as a function of fluid velocity for four sheated thermocouples with different diameters. To demonstrate the applicability of the presented method to actual data where air velocity varies, the temperature of air is estimated based on measurements carried out by three thermocouples with different outer diameters. Lastly, the time constant is presented as a function of fluid velocity and outer diameter of thermocouple.
50
Bhattacharya, S., H. Behlow, I. Rancu, A. M. Rao, and H. J. Goldsmid. "Thermoelectric figure-of-merit from Peltier cooling." Journal of Applied Physics 132, no. 17 (November 7, 2022): 175106. http://dx.doi.org/10.1063/5.0116327.
Full textAbstract:
We use Peltier cooling to experimentally determine the thermoelectric figure-of-merit of a material, where the maximum temperature depression, Δ Tmax, is simply related to Z of a thermocouple. However, for thermocouples comprising good thermoelectric materials with [Formula: see text], Δ Tmax can be large (≥100 K), making it difficult to assign the measurement to a particular temperature. This is less of a problem if the thermocouple consists of a semiconductor and a metal since Z T and Δ Tmax are then much smaller. We developed a procedure for measuring the dimensionless figure-of-merit of a semiconductor using semiconductor-metal thermocouples in which the form factor (i.e., the ratio of areas to lengths of the two branches) is optimized. We also show valuable aspects in the Δ Tmax measurement when the material dimensions are varied. Our experiments on couples consisting of a bismuth telluride alloy and constantan, and the corresponding theoretical analysis, show that the radiation losses are significant at ordinary temperatures. A good estimate of thermal conductivity and zT of the sample can be obtained when radiation losses are minimized.