Precise temperature controller for resistance thermometers

2019

The work investigated the responses of measuring and calibrating temperature in the range of 30 to 60°C in a computer controlled tray drier using a setup of TH1. The setup was configured with an ice flask, sensor installing unit, an electrical console, and a regulating bath, which can withstand temperatures in the range of 0°C to 100°C. Various sensors such as industrial platinum resistance thermometer PT100IND, type K thermocouple, and a thermistor were installed. The setup was configured with highly accurate reference sensors of platinum resistance device PT100 with NAMAS calibration certificate and temperature with linearized output. Extra reference sensors have been installed such as bi-metallic and liquid-in-glass thermometers to ensure high accuracy in measuring and calibrating data. The experimental data revealed that the PT100IND resistance changed linearly with temperature. The calibration error of PT100IND and according to the temperature data of the drier unit reached a m...

Zenodo (CERN European Organization for Nuclear Research), 2022

Measurement of temperature is an important aspect of any system such as an experimental system, equipment or any process involving the temperature. The measurement and control of temperature is quite important for the proper functioning of the process, device, or the equipment. Especially, in the field of cryogenics, there is a need to measure temperatures of fluids entering or exiting systems such as a Joule Thompson (JT) valve, an expansion engine or a turbine to assess the performances and improve them. Measurement of temperatures in the cryogenic range is carried out by different transducers such as the Resistance Temperature Detectors (RTD)s (also known as Resistance Thermometers, such as Platinum resistance thermometer (PT500)), thermocouples, Cernox, Silicon diodes and Germanium sensors etc. The sensors produce an output proportional to the variation of some physical property with temperature. The temperature calibration of the above sensors is best done against a pre-calibrated temperature sensor. In this work, we present the development of a variable temperature experimental setup using a two stage Gifford McMahon (GM) cryocooler, which provides the refrigeration to cover the temperature range from 4.2 K to 300 K needed for the temperature sensor calibration. The sensors to be calibrated are mounted within the holes of an Oxygen Free High Conductivity (OFHC) copper thermal block, which accommodates a maximum of eight temperature sensors. Its design is such that different types of temperature sensors such as Silicon / Germanium diodes, RTDs, Thermocouples, Cernox sensors, Carbon resistors etc. can be calibrated using a pre-calibrated Silicon diode temperature sensor. The sensor leads from the vacuum jacket of the experimental cryostat are connected to the measuring instruments which consist of a current source (Source meter), Data AcQuisition System (DAQ), a Temperature controller and a computer. An in-house developed LabVIEW based software is used for the temperature control of the copper lock and data collection. The results of calibration of typical temperature sensors along with their measurement accuracies are presented. This set up is in regular use for the calibration of various types of temperature sensors.

CAS '99 Proceedings. 1999 International Semiconductor Conference (Cat. No.99TH8389), 1999

ABSTRACT We have developed and investigated several types of miniature cryogenic resistance thermometers based on germanium films on gallium arsenide and silicon thermodiode temperature sensors. A small-scale production of these devices is organized. The temperature measurement intervals of the resistance thermometers cover the 25 mK to 300 K temperature range, while those of thermodiodes cover the 4 to 600 K temperature range

BIALIG, 2019

Temperature is one of the most followed parameters in engineering. It needs to be monitored in many control processes. Some areas where temperature information is used; Food processing, heating and cooling systems, healthcare and production processes. For this purpose, many different methods have been developed to measure the temperature. In this study, the sensors used for temperature measurement will be examined. Parameters such as measuring the working conditions of these sensors, sensitivity of response times will be discussed. Some of the classical and commonly used thermistors (NTC, PTC), RTDs (PT100), thermocouples and semiconductor LM35, DS1820, and other electronic chips produced in recent years will be discussed and their different aspects will be emphasized. In this way, information about the choice of temperature perceptions that can be used in academic or commercial applications will be presented.

International Journal of Thermophysics, 2011

This article presents the modification and testing of an ADC-based thermometry bridge. The instrument under investigation is an Anton Paar MKT 50 Millikelvin Thermometer (developed at the IFE, TU-Graz) based on a precision analog-to-digital converter (ADC). During preliminary testing, it was found that the MKT 50 performs better than its declared uncertainty (1 mK equal to 1 ppm when using a 100 PRT) and is comparable to thermometry resistance ratio bridges typically used in secondary thermometry laboratories (with typical uncertainties from 0.1 mK to 1 mK). The modifications to the original bridge were undertaken by the development team of the MKT 50 at the Graz University of Technology, Austria. Measurements and evaluation of the modified instruments were performed at the MIRS/UL-FE/LMK. For the MKT 50 to be used in thermometry laboratories as a reference unit, measuring parameters of the instrument had to be changed. During the first modification, the upper limit of the instrument range was decreased from 400 to 133 , this is a preferred range for standard platinum resistance thermometers (SPRTs). This also meant an increase in the measuring current from 0.5 mA to the more frequently used 1 mA. A modification of the programmable ADC control unit increased the resolution from 24 bit to 27 bit. By adding a switch, the use of an external standard resistor was enabled. After this stage of the modification, the first tests on the instrument were performed. The second stage was aimed at the removal of noise sources. The instrument was

Measurement, 2008

for resistance-versus-temperature (R-T) dependence of negative temperature coefficient resistors (NTCRs), which have resistance R N = 10,000 X at a temperature of 25°C and limits of error ±0.2°C in the range from 0°C to 70°C [Fenwal Electronics Catalog: Thermistoren UNI Kurve; Typ: UUA41J1, UUA41J8 (10 kX at 25°C, limits of error ±0.2°C in the range from 0°C to 70°C); BetaTHERM Sensors, http://www.betatherm.com; BetaCURVE Thermistor Series III 10K3A1W2 (10 kX at 25°C, limits of error ±0.2°C in the range from 0°C to 70°C), http://www.betatherm.com/datasheets/datasheet.php?p_id=69#; Advanced Thermal Products, http://www.atpsensor.com/; coated chip thermistor A1004-C3 (10 kX at 25°C, limits of error ±0.2°C in the range from 0°C to 70°C), http://www.atpsensor.com/ntc/ntc_rvt_pdfs/rvt_pdf.html; Epcos, http://www.epcos.com; uni-curve NTC thermistor S 863/10k/F40 (10 kX at 25°C, limits of error ±0.2°C in the range from 0°C to 70°C), http://www.epcos.com/inf/50/db/ntc_02/ 00920093.pdf], are analysed. Determination of two approximation curves is described: a three-parameter one (abbreviated AC1) and a two-parameter one (AC2). These curves are compared with the three-parameter Steinhart-Hart equation (S&H) by using the table data of resistance for different NTCRs and calculating the following for all of them: unknown parameters by the least-squares method, approximated temperature using determined parameters, and the difference from the table data of temperature. The obtained results are presented, showing a very good agreement of curves, with their mutual differences within a few millikelvins, and the differences from the table data mostly within ±10 mK for the range from 0°C to 70°C (differences are larger only at a few points). Therefore, the presented two-parameter approximation curve AC2 can be very conveniently used with some NTCRs for the calculation of unknown temperature from the measured resistance.

International Journal of Thermophysics, 2008

At the Italian National Research Institute of Metrology, the activities and studies concerning gas-controlled heat pipes are constantly increasing in terms of involved personnel, instrumentation, and devices available. In the last two years, among the other activities, a totally new gas-controlled heat pipe operating with mercury as the working fluid has been designed, manufactured, and completely characterized. This heat pipe is made of stainless steel and provided with three thermometer wells. A dedicated furnace has been constructed and specific software algorithms have been implemented for the temperature and pressure control. This device will be used as a low-temperature reference for the new "Temperature Amplifier" and as a calibration facility for thermometers calibrated by comparison between 220 • C and 450 • C. All details regarding this heat pipe, including the assembly, filling, and testing procedures, and the complete characterization campaign are summarized here. Results in terms of temperature stability, uniformity, and time response are reported, and demonstrate the capabilities of this gas-controlled heat pipe to be a useful device for research and applications in contact thermometry. Another gas-controlled heat pipe operating with mercury and provided with six thermometer wells has been manufactured, and will be characterized for the contact thermometry calibration laboratory at INRiM and for other calibration companies in Italy; this device is also presented.

IJSRD, 2013

The continuous monitoring of liquid temperature in cryogenic application is essential requirement from control and safety point of view. . Several factors must be considered when selecting the type of sensor to be used in a specific application Any temperature dependent parameter can be used as a sensor if it fits the requirements of the given application. These parameters include resistance, forward voltage (diodes), thermal EMFs, capacitance, expansion/contraction of various materials, magnetic properties, noise properties, nuclear orientation properties, etc. The two most commonly used parameters in cryogenic are voltage (diodes) and resistance. There are several reasons for choosing diode thermometry or resistance thermometry. Therefore this paper present the demand of precision measurement of temperature is addressed using semiconductor diode type sensor and resistor type sensor by sensor characteristic.

Zenodo (CERN European Organization for Nuclear Research), 2022

The purpose of this project is the construction of a portable digital chemical thermometer and its comparison against analog thermometers to be applied as an experimental instrument in the chemistry laboratory where the temperature measurement is carried out in different chemical substances by students and teachers of the University. Technology of Tlaxcala. This article describes the comparison made after the construction of the digital chemical thermometer, a project carried out by students of the Industrial Maintenance career at the Technological University of Tlaxcala. First, a plastic structure was manufactured in a 3D printer, then an Atmel 328P microcontroller was used to control the thermometer, a 128x64 OLED screen to display the temperature, a J-type thermocouple adapted with a MAX6633 was used as a sensor that is responsible for obtaining temperature data and a recharging module for a rechargeable 9V lithium-ion battery. Its purpose is to obtain a precise temperature measurement of substances, thus being a more reliable and easy-to-use measuring instrument for the student community. Its design is a rectangular box-shaped structure, this design was made in the Solid Works design software, once the design was finished it was exported to the Ultimaker software to print it in 3D, then the different pieces were assembled by joining them with bolts for later, assembling the electronic circuit inside the box, programming the Atmel 328P microcontroller, and finally calibrating the J-type thermocouple. By performing comparative tests in ice water up to the boiling point at different temperatures against an analog mercury device, as well as a device of alcohol, it was possible to observe a great similarity in the values obtained, for which it was verified that the thermometer works correctly, is reliable and meets the needs of the university.