The NIST Industrial Thermometer Calibration Laboratory

Published

June 1, 2001

Author(s)

C D. Vaughn, Gregory F. Strouse

Abstract

The NIST Industrial Thermometer Calibration (ITC) Laboratory provides calibrations of industrial thermometers over the range from 196 C to 550 C. The different types of thermometers include liquid-in-glass (LiG), thermistors, thermocouples (<300 C), and industrial platinum resistance thermometers (IPRTs). Calibrations are performed by both comparison with an International Temperature Scale of 1990 a standard platinum resistance thermometer (SPRT) calibrated on the International Temperature Scale of 1990 and by a limited number of fixed-points. The comparison baths are liquid nitrogen ( 196 C), alcohol ( 100 C to 1 C), water (0.5 C to 95 C), oil (95 C to 275 C), and salt (275 C to 550 C). The fixed points used are the melting point of ice (0 C), the triple point of water (0.01 C), and the melting point of gallium (29.7646 C). The temperature measurement system for the reference SPRT is a commercially-available ac resistance ratio bridge, for the IPRTs and thermistors it is a dc voltmeter with a constant current source, for the thermocouples it is a dc voltmeter, and for the LiGs it is a digital video camera. All of these temperature measurement systems are integrated via three computer-controlled data acquisition systems that semi-automate calibrations. This paper presents the methods, equipment, and uncertainties associated with the calibration of industrial thermometers in the ITC Laboratory.

Proceedings Title

International Symposium on Temperature and Thermal Measurements in Industry and Science | 8th | | VDE

Conference Dates

June 1, 2001

Conference Location

Berlin, 1, GE

Conference Title

TEMPMEKO

Pub Type

Conferences

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Keywords

Digitals, Industrial Thermometers, ITS-90, Liquid-in-glass, Resistance Thermometers, Thermistors, Thermocouples, Thermometer Calibrations, Thermometry

Citation

Vaughn, C. and Strouse, G. (2001), The NIST Industrial Thermometer Calibration Laboratory, International Symposium on Temperature and Thermal Measurements in Industry and Science | 8th | | VDE, Berlin, 1, GE, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=830734 (Accessed July 23, 2025)