Zhimin P.,Tsinghua University |
Yanjun D.,Tsinghua University |
Junwei J.,Beijing Orient Institute for Measurement and Test |
Lijuan L.,Tsinghua University |
Zheng L.,Tsinghua University
Optics Express | Year: 2013
Integrated absorbance (IA) can be used to infer gas temperature and concentration directly, in this paper, we proposed a new method that uses the 1st harmonic to measure the IA under low absorption conditions (<10%). Subsequently, a large number of numerical simulations are used to validate the reliability and accuracy of this method, and several absorption lines of CO2 and H2O molecules near 6981 cm-1 are selected to determine the IA and species concentration in experiments. Calculation and experiment results show that the proposed method can accurately measure IA in actual measurements. © 2013 Optical Society of America.
Lan L.-J.,Tsinghua University |
Ding Y.-J.,Tsinghua University |
Jia J.-W.,Beijing Orient Institute for Measurement and Test |
Du Y.-J.,Tsinghua University |
Peng Z.-M.,Tsinghua University
Wuli Xuebao/Acta Physica Sinica | Year: 2014
Measuring the temperature in vacuum environment is more complex than in atmospheric environment. For example, high vacuum will cause the thermocouple sensor surface desorption, and the mechanism of heat transfer is also different. Therefore, there are some uncertainties if the thermocouple is used to measure the gas temperature in vacuum condition. In the present paper, tunable diode laser absorption spectroscopy (TDLAS) is employed to measure the gas temperature and also explore the application prospect of TDLAS temperature measurement technology in vacuum environment. During the thermal vacuum experiments, the vacuum gas cell is immersed in the thermostatic bath, and the gas temperature is determined by TDLAS. Meanwhile, a standard Pt-resistance is used to measure the thermostatic bath temperature. The results show that the temperatures of the gas and thermostatic bath are highly consistent with each other, and the difference between the two temperatures is less than ±0.2°C when the thermostatic bath is stable. © 2014 Chinese Physical Society.
Wang H.,China Institute of Metrology |
Lei M.,China Electric Power Research Institute |
Zhang J.,China Electric Power Research Institute |
Sun Y.,Beijing Orient Institute for Measurement and Test |
And 5 more authors.
Gaoya Dianqi/High Voltage Apparatus | Year: 2012
In this paper, a measuring standard equipment of high voltage switch mechanical characteristic testing instrument is developed, which can use for calibration of high voltage switch mechanical characteristic testing instrument efficiently. The standard equipment based on ARM and FPGA technique, use COPLEY linear motor TBX-2504 as speed module, use high speed MOSFET as speed signal and time signal. According to the test data provided by National Legal Metrology Institutions, the device performance parameters meet the design requirements.
Jia J.,Beijing Orient Institute for Measurement and Test |
Zhang S.,Beijing Orient Institute for Measurement and Test |
Peng Z.,Tsinghua University |
Chai H.,Beijing Orient Institute for Measurement and Test |
And 3 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2014
A novel technique was developed to measure and calibrate gas temperature in vacuum by tunable diode laser absorption spectroscopy (TDLAS) in wavelength modulation spectroscopy (WMS) mode. The traceability and mea-surement error were experimentally investigated and error-analysis was performed. The rotation-vibration temperature of C2H2 molecules was measured and calibrated in vacuum by evaluating a well-chosen pair of spectral lines around 6558 cm" and with a lab-built calibrator, Grade-1 Pt-resistance thermometer as the standard, and a high precision thermostat as the heat source. The results show tht the newly-developed TDLAS technique is capable of measuring the rotation-vibration temperature of C2H2 molecules in vacuum with high sensitivity and good stability in low to medium temperature range. For example, the experimental uncertainty was U=0.24℃, k=2, and the discrepancy between the results measured by TDLAS and the Pt-resistance thermometer was within ±0.2℃.
Tong Y.,Beijing Orient Institute for Measurement and Test |
Huang X.,Beijing Orient Institute for Measurement and Test
2015 IEEE 12th International Conference on Electronic Measurement and Instruments, ICEMI 2015 | Year: 2016
Since the AC resistance measuring meter and the bridge adopt measurement principle of the four-terminal-pair, but the resistor with calculable frequency dependence is usually the four-terminal structure. So it is necessary to design a four-terminal-pair resistor with calculable frequency dependence. This paper introduces the 100Ω coaxial resistor with calculable frequency dependence based on four-terminal-pair. It introduces the structure and parameters of the resistance sample, builds the coaxial resistance's mathematical model and calculates the related parameters. Calculated AC-DC difference is only a few parts in 10-11 at a frequency of 1kHz, the time constant of the resistance is 3.6×10-9s. By comparing with the measuring result, both have a good consistency. © 2015 IEEE.