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Journal articles on the topic 'Measurement chamber'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

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1

Cazorla, M., and W. H. Brune. "Measurement of Ozone Production Sensor." Atmospheric Measurement Techniques 3, no. 3 (2010): 545–55. http://dx.doi.org/10.5194/amt-3-545-2010.

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Abstract. A new ambient air monitor, the Measurement of Ozone Production Sensor (MOPS), measures directly the rate of ozone production in the atmosphere. The sensor consists of two 11.3 L environmental chambers made of UV-transmitting Teflon film, a unit to convert NO2 to O3, and a modified ozone monitor. In the sample chamber, flowing ambient air is exposed to the sunlight so that ozone is produced just as it is in the atmosphere. In the second chamber, called the reference chamber, a UV-blocking film over the Teflon film prevents ozone formation but allows other processes to occur as they do

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2

Cazorla, M., and W. H. Brune. "Measurement of ozone production sensor." Atmospheric Measurement Techniques Discussions 2, no. 6 (2009): 3339–68. http://dx.doi.org/10.5194/amtd-2-3339-2009.

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Abstract. A new ambient air monitor, the Measurement of Ozone Production Sensor (MOPS), measures directly the rate of ozone production in the atmosphere. The sensor consists of two 11.3 L environmental chambers made of UV-transmitting Teflon film, a unit to convert NO2 to O3, and a modified ozone monitor. In the sample chamber, flowing ambient air is exposed to the sunlight so that ozone is produced just as it is in the atmosphere. In the second chamber, called the reference chamber, a UV-blocking film over the Teflon film prevents ozone formation but allows other processes to occur as they do

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3

Cai, Zhanghua, Yantao Zhou, Lie Liu, Francesco de Paulis, Yihong Qi, and Antonio Orlandi. "A Method for Measuring the Maximum Measurable Gain of a Passive Intermodulation Chamber." Electronics 10, no. 7 (2021): 770. http://dx.doi.org/10.3390/electronics10070770.

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This paper presents an approximate method that allows the calculation of the maximum measurable gain (MMG) in an anechoic chamber. This method is realized by using a low passive intermodulation (PIM) medium-gain directional antenna. By reducing the distance between the antenna and the wall of the chamber to reduce path loss, the purpose of replacing a high-gain antenna with a medium-gain antenna is achieved. The specific relationship between distance and equivalent gain is given in this paper. The measurement interval is determined by the 3 dB beamwidth of the measurement antenna to scan the w

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Juszczak, R. "Biases in methane chamber measurements in peatlands." International Agrophysics 27, no. 2 (2013): 159–68. http://dx.doi.org/10.2478/v10247-012-0081-z.

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Abstract The paper presents results of CH4 emission measurements at peatland with the application of the dynamic chamber technique. The measurements were conducted in two types of chambers differing in shape, height, volume and technology used to assure their tightness. The study tested how the following factors: 1) forced chamber headspace mixing or its absence, 2) mistakes of the person conducting measurements, 3) improper application of linear technique for calculating CH4 fluxes, and 4) simulated air sampling typical for static chambers, influence the significance of errors and the underes

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Meyer, Carsten H., Stefan Mennel, Carlos Cury, and Walter Sekundo. "Anterior Chamber Width Measurement." Ophthalmology 112, no. 9 (2005): 1638–39. http://dx.doi.org/10.1016/j.ophtha.2005.03.005.

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Pirkl, R. J., K. A. Remley, and C. S. L. Patane. "Reverberation Chamber Measurement Correlation." IEEE Transactions on Electromagnetic Compatibility 54, no. 3 (2012): 533–45. http://dx.doi.org/10.1109/temc.2011.2166964.

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7

Akber, Syed F., and Than S. Kehwar. "Partial volume characteristics of ionization chambers in kilovoltage x-ray exposure measurements." Journal of Radiotherapy in Practice 11, no. 3 (2011): 184–88. http://dx.doi.org/10.1017/s1460396911000252.

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AbstractThe partial volume (spatial) response of four ionization chambers (Keithley) in kilovoltage X-ray beams, generated by the Philips Super 80CP X-ray unit, was assessed. The volume of the ionization chambers were of 10 cm3, 15 cm3, 150 cm3, and 600 cm3 used with Keithley electrometer Model 35040. The beam output was measured using a monitor chamber (Radcal 6.0 cm3) placed close to the collimator. The source to chamber distance was kept constant at 1 m. For the measurement of the response of ionization chambers of 15 cm3, 150 cm3, and 600 cm3, a slit of 2.0 mm width was made in a lead shee

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Begum, Afia, and Nobuhisa Takata. "Recombination Parameters of some Fabricated Ionization Chambers." Bangladesh Journal of Medical Physics 4, no. 1 (2013): 101–6. http://dx.doi.org/10.3329/bjmp.v4i1.14694.

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Some pancake and spherical type ionization chambers of various size have been designed and fabricated for absolute air kerma measurement in 60Co and 137Cs ?-ray fields at the Primary Standard Dosimetry Laboratory (PSDL), National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Japan. Values of recombination parameters A and m2g of these ionization chambers are obtained using a method proposed by De Almeida and Niatel and adopted by Boutillon. For absolute air kerma measurement, it is important to obtain accurate signal currents by correcting it for ion losses using t

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Djordjevic, Antonije, Dragan Olcan, Jovana Petrovic, Nina Obradovic, and Suzana Filipovic. "High-accuracy quasistatic numerical model for bodies of revolution tailored for RF measurements of dielectric parameters." Facta universitatis - series: Electronics and Energetics 34, no. 1 (2021): 141–56. http://dx.doi.org/10.2298/fuee2101141d.

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We have developed rotationally symmetrical coaxial chambers for measurements of dielectric parameters of disk-shaped samples, in the frequency range from 1 MHz to several hundred MHz. The reflection coefficient of the chamber is measured and the dielectric parameters are hence extracted utilizing a high-accuracy quasistatic numerical model of the chamber and the sample. We present this model, which is based on the method of-moments solution of a set of integral equations for composite metallic and dielectric bodies. The equations are tailored to bodies of revolution. The model is efficient and

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10

Knox Cartwright, N. E., and D. M. Tole. "Pseudophakic anterior chamber depth measurement." Eye 23, no. 11 (2009): 2120. http://dx.doi.org/10.1038/eye.2008.407.

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11

Klein, L., and A. D. G. Wright. "Construction and operation of open-circuit methane chambers for small ruminants." Australian Journal of Experimental Agriculture 46, no. 10 (2006): 1257. http://dx.doi.org/10.1071/ea05340.

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A detailed description of the construction, calibration and operation of 4 open-circuit chambers designed to measure methane emissions from sheep is given. These chambers have accommodated sheep under ad libitum feeding and have been used in short-term experiments and over extended periods of time. A real-time base data acquisition and process control system provided 24 h operation of the methane chambers. The gas volume measurement system consisted of dry test meters and sensors for differential and absolute pressure, temperature and relative humidity. This enabled correction of methane chamb

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Mustapha, H., K. H. Ismail, T. J. Daim, and S. F. Jamil. "Performance Testing of Anechoic Chamber." Applied Mechanics and Materials 629 (October 2014): 252–56. http://dx.doi.org/10.4028/www.scientific.net/amm.629.252.

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Anechoic chambers are widely used in performing EMC measurements according to the established EMC standards. In space area, the elements of EMC measurements such as emission, immunity and susceptibility are critically important to ascertain that all of electrical and electronic components in the satellite body will function correctly without fail, thus ensures the smoothness of satellite operation upon launching into space. Realising this, level of anechoic chamber performance should always be in the optimum state as possible. This paper presents the specific tests that were carried out in the

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Gururani, Deepshikha, Harish S. Rawat, Satya K. Dubey, and V. N. Ojha. "Total Radiated Power Measurement in an Uncalibrated Reverberation Chamber." Defence Science Journal 69, no. 5 (2019): 427–30. http://dx.doi.org/10.14429/dsj.69.14945.

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With the increased use of wireless communication in recent years, the use of reverberation chamber (RC) has increased to a great extent. Reverberation chambers have been eminently used for EMC testing and shielding effectiveness. The environment it provides is very similar to the reverberant surroundings that antenna undergoes in real life use. An experiment to measure total radiated power of antenna, antenna efficiency and quality factor of chamber in indoor environment is proposed. This will make the measurement very simple and inexpensive as designing and calibration of chamber will not be

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Lorke, A., P. Bodmer, C. Noss, et al. "Technical note: drifting versus anchored flux chambers for measuring greenhouse gas emissions from running waters." Biogeosciences 12, no. 23 (2015): 7013–24. http://dx.doi.org/10.5194/bg-12-7013-2015.

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Abstract. Stream networks have recently been discovered to be major but poorly constrained natural greenhouse gas (GHG) sources. A fundamental problem is that several measurement approaches have been used without cross-comparisons. Flux chambers represent a potentially powerful methodological approach if robust and reliable ways to use chambers on running water can be defined. Here we compare the use of anchored and freely drifting chambers on various streams with different flow velocities. The study clearly shows that (1) anchored chambers enhance turbulence under the chambers and thus elevat

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Hao, Ryan, and Ning Xiang. "Diffusion equation modelling for energy flow analysis in reverberation chambers." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 1 (2021): 5637–42. http://dx.doi.org/10.3397/in-2021-3197.

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Noise is a growing concern in the built environment. Sound absorbers are a viable option for noise treatment. However, the characterization of their absorption coefficient in standardized measurement chambers still show challenges for high accuracy as required in practice. In recent years, experimental analysis has shown that assumptions of diffuse sound fields made in well-known reverberation chambers are unfulfilled. Specifically, that sound intensities in chamber-based measurement methods are presumed to be isotropic or diffuse. Diffusion equation models have shown dramatic changes in energ

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Lorke, A., P. Bodmer, C. Noss, et al. "Technical Note: Drifting vs. anchored flux chambers for measuring greenhouse gas emissions from running waters." Biogeosciences Discussions 12, no. 17 (2015): 14619–45. http://dx.doi.org/10.5194/bgd-12-14619-2015.

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Abstract. Stream networks were recently discovered as major but poorly constrained natural greenhouse gas (GHG) sources. A fundamental problem is that several measurement approaches have been used without cross comparisons. Flux chambers represent a potentially powerful methodological approach if robust and reliable ways to use chambers on running water can be defined. Here we compare the use of anchored and freely drifting chambers on various streams having different flow velocities. The study clearly shows that (1) drifting chambers have a very small impact on the water turbulence under the

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17

Parker, David B., Kenneth D. Casey, Richard W. Todd, et al. "Improved Chamber Systems for Rapid, Real-Time Nitrous Oxide Emissions from Manure and Soil." Transactions of the ASABE 60, no. 4 (2017): 1235–58. http://dx.doi.org/10.13031/trans.12151.

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Abstract. Nitrous oxide (N2O) emission rates have traditionally been measured using non-flow-through (NFT), non-steady-state (NSS) chambers, which rely on measuring the increase in N2O concentration in the sealed chamber headspace over time. These flux measurements are very labor- and time-intensive, requiring three to four gas samples collected over a 30 to 60 min period, followed by laboratory N2O measurement with a gas chromatograph (GC) and subsequent flux rate calculation. The objective of this research was to develop and evaluate improved, real-time flux chamber designs that rapidly quan

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18

Zhao, Yiguang, Xuemei Nan, Liang Yang, Shanshan Zheng, Linshu Jiang, and Benhai Xiong. "A Review of Enteric Methane Emission Measurement Techniques in Ruminants." Animals 10, no. 6 (2020): 1004. http://dx.doi.org/10.3390/ani10061004.

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To identify relationships between animal, dietary and management factors and the resulting methane (CH4) emissions, and to identify potential mitigation strategies for CH4 production, it is vital to develop reliable and accurate CH4 measurement techniques. This review outlines various methods for measuring enteric CH4 emissions from ruminants such as respiration chambers (RC), sulphur hexafluoride (SF6) tracer, GreenFeed, sniffer method, ventilated hood, facemask, laser CH4 detector and portable accumulation chamber. The advantages and disadvantages of these techniques are discussed. In genera

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19

Faul, Fabian T., Hans-Jürgen Steiner, and Thomas F. Eibert. "Near-Field Antenna Measurements with Manual Collection of the Measurement Samples." Advances in Radio Science 18 (December 10, 2020): 17–22. http://dx.doi.org/10.5194/ars-18-17-2020.

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Abstract. Near-field measurements are commonly performed in anechoic chambers which limits the flexibility of the measurements and requires high precision equipment to achieve exact results. In this contribution, we investigate a simple near-field measurement setup which does not use any sophisticated positioning system nor operates in a controlled environment. Instead, the probe antenna is moved by an operator person while the probe position is measured by a laser tracker. This implies that the measurement results will have a higher error level in comparison with antenna chamber measurements.

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Drewry, Jessica L., J. Mark Powell, and Christopher Y. Choi. "Design and Calibration of Chambers for the Measurement of Housed Dairy Cow Gaseous Emissions." Transactions of the ASABE 60, no. 4 (2017): 1291–300. http://dx.doi.org/10.13031/trans.12046.

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Abstract. The increased global demand for milk and other dairy products over the past decade has heightened concerns about the potential for increased environmental impacts. Accurate measurement of gas emissions from dairy cows is essential to assess the effects of cow diets and other management practices on both the composition and rate of gas emissions. In this article, methodologies are described to instrument, calibrate, and assess the uncertainty of gas emissions by cows housed in chambers that simulate production settings. The supply and exhaust ducts of each chamber were equipped with p

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Almand-Hunter, B. B., J. T. Walker, N. P. Masson, L. Hafford, and M. P. Hannigan. "Development and validation of inexpensive, automated, dynamic flux chambers." Atmospheric Measurement Techniques Discussions 7, no. 7 (2014): 6877–915. http://dx.doi.org/10.5194/amtd-7-6877-2014.

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Abstract. We developed and validated an automated, inexpensive, and continuous multiple-species gas-flux monitoring system that can provide data for a variety of relevant atmospheric pollutants, including O3, CO2, and NOx. Validation consisted of conducting concurrent gas-phase dry-deposition experiments, using both dynamic flux chambers and an eddy-covariance system, in a grassy clearing in the Duke Forest (Chapel Hill, NC). Experiments were carried out in June and September, under a variety of meteorological conditions. Ozone-deposition measurements from the two methods matched very well (4–

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Teske, Jennifer A., Claudio E. Perez-Leighton, Charles J. Billington, and Catherine M. Kotz. "Methodological considerations for measuring spontaneous physical activity in rodents." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 306, no. 10 (2014): R714—R721. http://dx.doi.org/10.1152/ajpregu.00479.2013.

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When exploring biological determinants of spontaneous physical activity (SPA), it is critical to consider whether methodological factors differentially affect rodents and the measured SPA. We determined whether acclimation time, sensory stimulation, vendor, or chamber size affected measures in rodents with varying propensity for SPA. We used principal component analysis to determine which SPA components (ambulatory and vertical counts, time in SPA, and distance traveled) best described the variability in SPA measurements. We compared radiotelemetry and infrared photobeams used to measure SPA a

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23

Rhee, Eugene, and Ji Hoon Lee. "EMC Measurement in a Reverberation Chamber." Applied Mechanics and Materials 339 (July 2013): 436–39. http://dx.doi.org/10.4028/www.scientific.net/amm.339.436.

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A reverberation chamber, which is a test facility for various electromagnetic compatibility tests, uses a stirrer to generate a uniform electric field inside it. However, a stirrer is a big unit and has difficulties in maintenance. This paper adopted an idea of a diffuser from acoustics to overcome the problems of a stirrer and presents a substitution effect of a diffuser for a stirrer. To validate the substitution effect of a diffuser, a diffuser and a reverberation chamber for 3.0-5.0 GHz band are designed and fabricated. And the real measurement for analyzing the electric field uniformity i

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Nanavaty, M. A., S. M. Raj, V. A. Vasavada, V. A. Vasavada, and A. R. Vasavada. "Reply: Pseudophakic anterior chamber depth measurement." Eye 23, no. 11 (2009): 2120. http://dx.doi.org/10.1038/eye.2008.408.

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Asada, Yasuki. "Measurement of Output by Ion Chamber." Japanese Journal of Radiological Technology 66, no. 4 (2010): 66_4_I. http://dx.doi.org/10.6009/jjrt.66.66_4_i.

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Saminathan, Sathiyan, Henry Finlay Godson, Retna Ponmalar, Ravikumar Manickam, James Mazarello, and Rahul Fernandes. "Dosimetric Performance of Newly Developed Farmer-Type Ionization Chamber in Radiotherapy Practice." Technology in Cancer Research & Treatment 15, no. 6 (2016): NP113—NP120. http://dx.doi.org/10.1177/1533034615621635.

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Dose measurement with ionization chamber is essential to deliver accurate dose to the tumor in radiotherapy. The cylindrical Farmer-type ionization chamber is recommended by various dosimetry protocols for dose measurement of radiotherapy beams. The air-equivalent graphite wall Farmer-type ionization chamber (FAR 65 GB) of active volume 0.65 cm3 with aluminum as the central electrode material was fabricated. Various dosimetric parameters were studied for the newly developed ionization chamber in cobalt-60, 6 and 18 MV photon beams. The preirradiation and postirradiation leakage of the chamber

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Pihlatie, M., J. Rinne, P. Ambus, et al. "Nitrous oxide emissions from a beech forest floor measured by eddy covariance and soil enclosure techniques." Biogeosciences Discussions 2, no. 3 (2005): 581–607. http://dx.doi.org/10.5194/bgd-2-581-2005.

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Abstract. Spring time soil nitrous oxide (N2O) fluxes were measured in an old beech (Fagus sylvatica L.) forest with eddy covariance (EC) and chamber techniques. The aim was to compare the two techniques and to test whether EC can be used in the trunk-space of the forest to measure N2O. Mean N2O fluxes over the five week measurement period were 5, 10 and 16 μg N m-2h-1 from EC, automatic chamber and manual chambers, respectively. When data from one hot spot chamber was excluded the mean N2O flux of 8 μg N m-2h-1 from the soil chambers nearly equaled to the mean flux of 7 μg N m-2h-1 measured w

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Kawashima, Kenji, Toshiharu Kagawa, and Toshinori Fujita. "Instantaneous Flow Rate Measurement of Ideal Gases." Journal of Dynamic Systems, Measurement, and Control 122, no. 1 (1996): 174–78. http://dx.doi.org/10.1115/1.482439.

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In this paper, a chamber called an “Isothermal Chamber” was developed. The isothermal chamber can almost realize isothermal condition due to larger heat transfer area and heat transfer coefficient by stuffing steel wool in it. Using this chamber, a simple method to measure flow rates of ideal gases was developed. As the process during charge or discharge is almost isothermal, instantaneous flow rates charged into or discharged from the chamber can be obtained measuring only pressure in the chamber. The steady and the unsteady flow rate of air were measured by the proposed method, and the effec

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Wippermann, Nicolas, Olaf Thiele, Olaf Toedter, and Thomas Koch. "Measurement of the air-to-fuel ratio inside a passive pre-chamber of a fired spark-ignition engine." Automotive and Engine Technology 5, no. 3-4 (2020): 147–57. http://dx.doi.org/10.1007/s41104-020-00067-w.

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Abstract This paper investigates the local air-to-fuel ratio measurement within the pre-chamber of a spark-ignition engine by determining the absorption of light from hydrocarbons using an infrared sensor. The measurement was performed during fired and motored engine operation points and compared to the more common exhaust lambda measurements. The experiment provided data to compare the mixture preparation in a hot and cold environment of pre-chamber and main combustion chamber. The experiment also gives an indication regarding the possible use of a pre-chamber sensor in a motored engine at hi

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Siegenthaler, A., B. Welch, S. R. Pangala, M. Peacock, and V. Gauci. "Technical Note: Semi-rigid chambers for methane gas flux measurements on tree-stems." Biogeosciences Discussions 12, no. 18 (2015): 16019–48. http://dx.doi.org/10.5194/bgd-12-16019-2015.

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Abstract. There is increasing interest in the measurement of methane (CH4) emissions from tree stems in a wide range of ecosystems so as to determine how they contribute to the total ecosystem flux. To date, tree CH4 fluxes are commonly measured using rigid closed chambers (static or dynamic), which often pose challenges as these are bulky and limit measurement of CH4 fluxes to only a very narrow range of tree stem sizes and shapes. To overcome these challenges we aimed to design, describe and test new semi-rigid stem-flux chambers (or sleeves). We compared semi-rigid chamber's gas permeabilit

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Senevirathna, D. G. M., G. Achari, and J. P. A. Hettiaratchi. "A laboratory evaluation of errors associated with the determination of landfill gas emissions." Canadian Journal of Civil Engineering 33, no. 3 (2006): 240–44. http://dx.doi.org/10.1139/l05-111.

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A laboratory investigation, supplemented with a theoretical analysis, was conducted to determine the errors associated with the closed flux chamber technique commonly used to determine the surficial gas emissions from landfills. The results indicate that the errors largely depend on the chamber dimensions, including chamber height, surface gas flux rate, and time interval over which the data are collected. Selection of a proper chamber height for a particular flux rate and the use of a short time period for measurement reduce the errors significantly.Key words: landfills, closed flux chambers,

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Anvari, Akbar, Seyed Mahmoud Reza Aghamiri, Seyed Rabie Mahdavi, and Parham Alaei. "Statistical analysis on 2D array of ion chamber performance." Journal of Radiotherapy in Practice 14, no. 2 (2015): 194–201. http://dx.doi.org/10.1017/s1460396914000442.

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AbstractPurposeIn this work, dosimetric properties of the PTW Octavius detector in and out of the irradiation field have been evaluated. The 2D array of ion chambers has the potential to simplify the linear accelerator QA and pre-treatment verification.Materials and methodsThe evaluation was performed using customised written codes in Matlab and SPSS software for statistical analysis.ResultsExperiments indicate that the reproducibility and stability of the measurements were excellent; the detector showed the same signal with a maximum deviation of <0·5% in the short and long term. Compariso

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Lawrence, Nathaniel C., and Steven J. Hall. "Capturing temporal heterogeneity in soil nitrous oxide fluxes with a robust and low-cost automated chamber apparatus." Atmospheric Measurement Techniques 13, no. 7 (2020): 4065–78. http://dx.doi.org/10.5194/amt-13-4065-2020.

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Abstract. Soils play an important role in Earth's climate system through their regulation of trace greenhouse gases. Despite decades of soil gas flux measurements using manual chamber methods, limited temporal coverage has led to high uncertainty in flux magnitude and variability, particularly during peak emission events. Automated chamber measurement systems can collect high-frequency (subdaily) measurements across various spatial scales but may be prohibitively expensive or incompatible with field conditions. Here we describe the construction and operational details for a robust, relatively

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Vojta, Lukas, and Vaclav Dvorak. "Measurement and calculating of supersonic ejectors." EPJ Web of Conferences 213 (2019): 02097. http://dx.doi.org/10.1051/epjconf/201921302097.

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This paper deals with numerical and experimental investigation of the flow in an air to air supersonic ejector with constant area mixing chamber. The mixing chamber of previous ejector was completely repaired since a scratch from previous turning had been found. As a result, a new geometry of the mixing chamber was created. Several measurements were conducted with different nozzle position (NP): 1 mm, 2 mm and 3 mm. Furthermore, for a given NP, two different values of stagnation pressure of 200 kPa and 300 kPa at the primary air inlet were investigated in more detail. All numerical simulations

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Corbella, Clara, and Jaume Puigagut. "Improving the reliability of closed chamber methodologies for methane emissions measurement in treatment wetlands." Water Science and Technology 68, no. 9 (2013): 2097–102. http://dx.doi.org/10.2166/wst.2013.469.

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Non-homogeneous mixing of methane (NHM) within closed chambers was studied under laboratory conditions. The experimental set-up consisted of a PVC vented chamber of 5.3 litres of effective volume fitted with a power-adjustable 12 V fan. NHM within the chamber was studied according to fan position (top vs lateral), fan airflow strength (23 vs 80 cubic feet per minute) and the mixing time before sample withdrawal (5, 10, 15 and 20 minutes). The potential bias of methane flux densities caused by NHM was addressed by monitoring the difference between linearly expected and estimated flux densities

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Koskinen, M., K. Minkkinen, P. Ojanen, M. Kämäräinen, T. Laurila, and A. Lohila. "Measurements of CO<sub>2</sub> exchange with an automated chamber system throughout the year: challenges in measuring night-time respiration on porous peat soil." Biogeosciences 11, no. 2 (2014): 347–63. http://dx.doi.org/10.5194/bg-11-347-2014.

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Abstract. We built an automatic chamber system to measure greenhouse gas (GHG) exchange in forested peatland ecosystems. We aimed to build a system robust enough which would work throughout the year and could measure through a changing snowpack in addition to producing annual GHG fluxes by integrating the measurements without the need of using models. The system worked rather well throughout the year, but it was not service free. Gap filling of data was still necessary. We observed problems in carbon dioxide (CO2) respiration flux estimation during calm summer nights, when a CO2 concentration

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ZHONG, RUILIN, JIAN WANG, CHANGQING CAI, et al. "AIR PRESSURE CONTROLLED MASS MEASUREMENT SYSTEM." International Journal of Modern Physics: Conference Series 24 (January 2013): 1360002. http://dx.doi.org/10.1142/s2010194513600021.

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Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the disp

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Jones, S. K., D. Famulari, C. F. Di Marco, et al. "Nitrous oxide emissions from managed grassland: a comparison of eddy covariance and static chamber measurements." Atmospheric Measurement Techniques Discussions 4, no. 1 (2011): 1079–112. http://dx.doi.org/10.5194/amtd-4-1079-2011.

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Abstract. Managed grasslands are known to be an important source of N2O with estimated global losses of 2.5 Tg N2O-N yr−1. Chambers are the most widely used method to measure N2O fluxes, but also micrometeorological methods have successfully been applied. In this paper we present a comparison of N2O fluxes measured by non-steady state chambers and eddy covariance (EC) (using an ultra-sonic anemometer coupled with a tunable diode laser) methods from an intensively grazed and fertilised grassland site in South East Scotland. The measurements were taken after fertilisation events in 2003, 2007 an

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Yi, Hongming, Mathieu Cazaunau, Aline Gratien, et al. "Intercomparison of IBBCEAS, NitroMAC and FTIR analyses for HONO, NO<sub>2</sub> and CH<sub>2</sub>O measurements during the reaction of NO<sub>2</sub> with H<sub>2</sub>O vapour in the simulation chamber CESAM." Atmospheric Measurement Techniques 14, no. 8 (2021): 5701–15. http://dx.doi.org/10.5194/amt-14-5701-2021.

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Abstract. We report on applications of the ultraviolet-light-emitting-diode-based incoherent broadband cavity-enhanced absorption spectroscopy (UV-LED-IBBCEAS) technique for optical monitoring of HONO, NO2 and CH2O in a simulation chamber. Performance intercomparison of UV-LED-IBBCEAS with a wet chemistry-based NitroMAC sensor and a Fourier transform infrared (FTIR) spectrometer has been carried out on real-time simultaneous measurement of HONO, NO2 and CH2O concentrations during the reaction of NO2 with H2O vapour in CESAM (French acronym for Experimental Multiphasic Atmospheric Simulation Ch

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Mustapha, Hafizah, K. H. Ismail, T. J. Daim, and S. F. Jamil. "A Review of Shielding Performance for Anechoic Chamber." Applied Mechanics and Materials 793 (September 2015): 600–604. http://dx.doi.org/10.4028/www.scientific.net/amm.793.600.

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Anechoic chambers are widely used in performing EMC measurements according to the established EMC standards. As in space area, EMC measurement is critically important to ascertain all of electrical and electronic components in the satellite body will function correctly without fail during launching and operation mode. Recognizing the needs and importance of performing the EMC measurements, the shielding performance of the chamber should be prioritized to ensure the interference of electromagnetic wave from outside going to inside the constructed chamber does not exist. As to maintain the shiel

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Bagoňa, Miloslav, Stanislav Tóth, and Richard Baláž. "Roof Structure Evaluation in Climatic Chamber Module." Advanced Materials Research 1041 (October 2014): 239–42. http://dx.doi.org/10.4028/www.scientific.net/amr.1041.239.

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The paper focuses on the assembly of equipment in experimental climate chambers with their respective sample envelopes and fenestration systems, which are involved in a measuring experiment. The prime aim is to design a logical and transparent system for gathering, evaluating and storing hygrothermal related data. This contribution further illustrates the installation of measurement points in test samples, the system of monitoring their physical properties, measurement results of roof system of the climatic chamber module and vapour barrier influence in roof structure on temperature damping ph

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Havranek, Wilhelm M., and Gerhard Wieser. "Design and testing of twig chambers for ozone fumigation and gas exchange measurements in mature trees." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 102 (1994): 541–46. http://dx.doi.org/10.1017/s0269727000014561.

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SynopsisA twig chamber system was developed for the exposure of mature trees to ozone (O3) under field conditions. The fumigation system allowed the exact control of O3 concentrations in the chambers, the measurement of O3 uptake as well as gas exchange measurements under ambient and controlled conditions during and after O3 fumigation. Because of differences in individual twigs the system should provide the exposure of replicates to different O3 treatments. Tests showed that temperature, humidity and O3 concentrations inside the chambers were comparable with diurnal courses observed in the fi

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Pape, L., C. Ammann, A. Nyfeler-Brunner, C. Spirig, K. Hens, and F. X. Meixner. "An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems." Biogeosciences 6, no. 3 (2009): 405–29. http://dx.doi.org/10.5194/bg-6-405-2009.

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Abstract. We present an automated dynamic chamber system which is optimised for continuous unattended flux measurements of multiple non-reactive and reactive trace gases on grassland ecosystems. Main design features of our system are (a) highly transparent chamber walls consisting of chemically inert material, (b) individual purging flow units for each chamber, and (c) a movable lid for automated opening and closing of the chamber. The purging flow rate was chosen high enough to keep the mean residence time of the chamber air below one minute. This guarantees a proven efficient mixing of the c

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Pape, L., C. Ammann, A. Nyfeler-Brunner, C. Spirig, K. Hens, and F. X. Meixner. "An automated dynamic chamber system for surface exchange measurement of non-reactive and reactive trace gases of grassland ecosystems." Biogeosciences Discussions 5, no. 4 (2008): 3157–219. http://dx.doi.org/10.5194/bgd-5-3157-2008.

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Abstract. We present an automated dynamic chamber system which is optimised for continuous unattended flux measurements of multiple non-reactive and reactive trace gases on grassland ecosystems. Main design features of our system are (a) highly transparent chamber walls consisting of chemically inert material, (b) individual purging flow units for each chamber, and (c) a movable lid for automated opening and closing of the chamber. The purging flow rate was chosen high enough to keep the mean residence time of the chamber air below one minute. This guarantees a proven efficient mixing of the c

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Geiling, Thomas, Tilo Welker, and Jens Müller. "Design, Fabrication, and Operation of a Nitrogen Measurement Device Based on LTCC." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (2012): 000167–74. http://dx.doi.org/10.4071/cicmt-2012-tp42.

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We present a so called micro total analytical system (μTAS) for the measurement of low nitrogen monoxide (NO) concentrations in gas flows. The measurement principle is based on the chemiluminescent reaction of NO with ozone (O3). The presented system scales down this measurement principle into the realm of micro fluidics and micro sensors. Low temperature co-fired ceramics (LTCC) have proven to be the ideal technology for the realization of a μTAS, as they offer high chemical and thermal stability as well as high degree of freedom of design. The system consists of 4 components: an ozone genera

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Even, Morgane, Olaf Wilke, Sabine Kalus, Petra Schultes, Christoph Hutzler, and Andreas Luch. "Formaldehyde Emissions from Wooden Toys: Comparison of Different Measurement Methods and Assessment of Exposure." Materials 14, no. 2 (2021): 262. http://dx.doi.org/10.3390/ma14020262.

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Formaldehyde is considered as carcinogenic and is emitted from particleboards and plywood used in toy manufacturing. Currently, the flask method is frequently used in Europe for market surveillance purposes to assess formaldehyde release from toys, but its concordance to levels measured in emission test chambers is poor. Surveillance laboratories are unable to afford laborious and expensive emission chamber testing to comply with a new amendment of the European Toy Directive; they need an alternative method that can provide reliable results. Therefore, the application of miniaturised emission

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Even, Morgane, Olaf Wilke, Sabine Kalus, Petra Schultes, Christoph Hutzler, and Andreas Luch. "Formaldehyde Emissions from Wooden Toys: Comparison of Different Measurement Methods and Assessment of Exposure." Materials 14, no. 2 (2021): 262. http://dx.doi.org/10.3390/ma14020262.

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Formaldehyde is considered as carcinogenic and is emitted from particleboards and plywood used in toy manufacturing. Currently, the flask method is frequently used in Europe for market surveillance purposes to assess formaldehyde release from toys, but its concordance to levels measured in emission test chambers is poor. Surveillance laboratories are unable to afford laborious and expensive emission chamber testing to comply with a new amendment of the European Toy Directive; they need an alternative method that can provide reliable results. Therefore, the application of miniaturised emission

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FUKUDA, Shota. "Measurement of chamber volumes and their function." Choonpa Igaku 41, no. 2 (2014): 143–54. http://dx.doi.org/10.3179/jjmu.jjmu.r.12.

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KATO, Shinichi, Junichiro KAMIYA, Kazami YAMAMOTO, Masahiro YOSHIMOTO, and Michikazu KINSHO. "Outgassing Rate Measurement of SUS430 Vacuum Chamber." Journal of the Vacuum Society of Japan 55, no. 4 (2012): 160–63. http://dx.doi.org/10.3131/jvsj2.55.160.

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Tristant, F., J. P. Moreau, and P. Levesque. "Electromagnetic measurement in a mode-stirred chamber." Microwave and Optical Technology Letters 28, no. 6 (2001): 417–21. http://dx.doi.org/10.1002/1098-2760(20010320)28:6<417::aid-mop1058>3.0.co;2-1.

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