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Gas temperature meter

Zashchepkina N. M., Svyta M. P.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 111, nr 1

33--41

EN

Purpose: of the article is to develop a digital portable gas temperature meter in the range of -50…+600°C. To measure the temperature of dusty gas flows in the air pollution sources with the least significant digit of the digital device 1°C. Design/methodology/approach: The microprocessor measuring unit, probe and software is proposed. It leads to build a high-precision temperature meter based on a thin film sensor HM220 type "pt100". Findings: The calculation of the electrical schematic diagram parameters for signal conditioning of the sensor relative to the input range of the analog-to-digital converter. The experimental measuring unit and the probe of the gas temperature meter are assembled. The principle of the gas temperature meter calibration with the help of a precision resistance box MSR-60M is considered. The experimental gas temperature meter has a total standard uncertainty determined by type B for a maximum value of the measurement range of 1.94°C. The error of the sensor "pt100" makes the largest contribution to the total standard uncertainty, so the error increases in proportion to the value of the measured temperature. Research limitations/implications: On the basis of the proposed design of gas temperature meter it is possible to construct devices with various lengths of probes. Practical implications: The proposed meter is designed for environmental laboratories that measure the velocity, flow and sampling of dust and gas emissions from sources of air pollution. Originality/value: The device design differs due to the use of thermostable wire made of constantan as extending conductors of the temperature sensor, which is included in the unbalanced Wheatstone bridge. This solution allows the use of unipolar power supply 3.3 V for both analog and digital part of the meter. Temperature meter based on a thin film resistance thermometer is characterized by relative ease of manufacture, low material consumption, cost and high reliability.

2

An improved resonant thermal converter based on micro-bridge resonator

Dong L., Han J., Zhang P., Zhao Z., Cheng B., Han D.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 4

715--725

EN

This paper presents the design, fabrication and testing of an improved thin-film thermal converter based on an electro-thermally excited and piezo-resistively detected micro-bridge resonator. The resonant thermal converter comprises a bifilar heater and an opposing micro-bridge resonator. When the micro-bridge resonator absorbs the radiant heat from the heater, its axial strain changes, then its resonant frequency follows. Therefore the alternating voltage or current can be transferred to the equivalent DC quantity. A non-contact temperature sensing mechanism eliminates heat loss from thermopiles and reduces coupling capacitance between the temperature sensor and the heater compared with traditional thin-film thermal converters based on thermopiles. In addition, the quasi-digital output of the resonant thin-film thermal converter eliminates such problems as intensity fluctuations associated with analogue signals output by traditional thin-film thermal converters. Using the fast-reversed DC (FRDC) method, the thermoelectric transfer difference, which determines the frequency-independent part of the ac-dc transfer difference, is evaluated to be as low as 1.1 · 10-6. It indicates that the non-contact temperature sensing mechanism is a feasible method to develop a high-performance thermal converter.

3

Toward extending the frequency of the AC–DC voltage transfer at Silesian University of Technology up to 10 MHz

Grzenik M., Kampik M.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 2

46--48

EN

The paper presents steps taken to extend the frequency range of the thermal AC-DC voltage transfer maintained at SUT up to 10 MHz. The properties of the measurement setup are described after replacing the Fluke 5700A calibrator used as AC voltage source up to 1 MHz with the Fluke 6071A RF signal generator. Next the results of the consistency checking of the AC–DC transfer difference measurements performed with the new measurement setup is presented. The results of verification of the correctness of the calculated and measured AC–DC transfer differences of the two calculable thermal AC voltage standards are presented in 1–10 MHz frequency range. The inconsistency of the measured AC–DC transfer difference is below 55 μV/V at 10 MHz, when comparing PMJTCs with SJTC and below 25 μV/V when comparing PMJTCs among themselves. The AC–DC transfer difference of the SUT calculable AC voltage standard was calculated from the modified mathematical model for frequencies up to 10 MHz. Direct comparison of the 3 V calculable AC voltage standard with the 5 V one confirmed correctness of the results obtained from the mathematical model.

4

Measurement system for investigation and calibration of digital sources of low-frequency AC voltage

Kampik M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1a

75--77

EN

The paper presents an automated measuring system for investigation and calibration of digital sources of low-frequency (1 mHz - 1 kHz) sinusoidal AC voltage. In frequency range from 10 Hz to 1 kHz the system allows the calibration of these sources with four methods: thermal, integrating sampling, step and peak-to-peak with uncertainty attaining approximately 1 μV/V. In frequency range from 1 mHz to 10 Hz it is possible to calibrate sources with three methods: integrating sampling, step and peak-to-peak with uncertainty 1 μV/V or better.

PL

W pracy przedstawiono zautomatyzowany system pomiarowy, przeznaczony do badań i wzorcowania cyfrowych źródeł napięcia przemiennego o małej częstotliwości. W paśmie częstotliwości od 10 Hz do 1 kHz system umożliwia wzorcowanie tych źródeł czterema metodami z niepewnością rzędu 1 μV/V.

5

Metoda wzorcowania planarnych wielozłączowych termicznych przetworników wartości skutecznej w zakresie częstotliwości 10, ..., 100 Hz

Kampik M.

Zeszyty Naukowe. Elektryka / Politechnika Śląska

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2004

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z. 190

7-16

PL

W pracy przedstawiono metodę wzorcowania termicznych przetworników wartości skutecznej (TPWS) napięcia przemiennego. Wzorcowanie polega na komparacji przetwornika wzorcowanego z TPWS o zredukowanej mocy wydzielanej w grzejniku. Komparacja jest realizowana w układzie napięciowego transferu ac-dc. W metodzie nie jest wymagane użycie wzorcowego TPWS o różnicy transferowej obliczonej z dużą dokładnością. Wymaga się jedynie, aby parametr ten był odpowiednio mały (<1x10 -5 miV/V) oraz aby przetwornik wzorcowy charakteryzował się dużą czułością. Warunki te spełniają planarne wielozłączowe przetworniki wartości skutecznej.

EN

The paper describes a method of calibration of thermal converters (TC) that are used as ac voltage standards. The calibration method is based on comparison of the thermal converter to be calibrated with the standard TC with reduced pewer developed in its heater. The calibration is performed in the ac-dc transfer measuring system. The method does not require a standard TC with accurately calculated ac-dc transfer difference. It is sufficient, when this parameter is small enough (<1x10 -5 miV/V) and the sensitivity of the standard TC is high. These conditions fulfill planar multijunction thermal converters (PMJTC).