A precise measurement of temperature difference using thermopiles
Journal
Experimental Thermal and Fluid Science
Journal Volume
3
Journal Issue
3
Pages
265-271
Date Issued
1990
Author(s)
URI
Abstract
The theory of thermopiles from multipairs of thermocouples for precise measurement of temperature difference ΔT was derived, and a calibration and signal conversion method using the theory was developed in the present study. The standard emf-T relation, E(T) or T(E), for thermopile was defined based upon the thermopile theory and can be determined by calibration against a precise thermometer and potentiometer. Then, a midpoint extrapolation method was applied to the emf-T curve of the thermopile to convert the measured emf signal to ΔT accurately. For purposes of illustration, a thermopile made from five pairs of T-type thermocouples was designed and calibrated by using the present method. It is shown that the uncertainty of this five-pair, T-type thermopile can be as low as ± 0.073°C, which has uncertainty less than ±2% for a ΔT of about ±3.5°C. © 1990.
SDGs
Type
journal article