METHOD FOR RUNNING ΔТ=f(I) CURVE FOR THERMOCOUPLE LEG Russian patent published in 2006 - IPC H01L35/34 

FIELD: thermoelectric instrumentation engineering; running curve of thermal cell leg temperature as function of electric current.

SUBSTANCE: leg under investigation is placed in evacuated chamber. One of butt-end surfaces of leg contacts switching wafer whose temperature is controlled. Other end surface of leg contacts reference specimen in the form of flexible bus of high heat conductivity whose loose end contacts other switching wafer cooled by cooler of adjustable cold productivity. Two junctions of differential thermocouple electrically connected to compensating microvoltmeter or to null-element are installed at respective points of contact between leg under investigation and second switching wafer. Electric current is passed through circuit set up of first switching wafer, leg under investigation, reference specimen, and second switching wafer. Signal is picked off differential thermocouple and set to zero by varying temperature of second switching wafer by means of cooler. Temperature difference through leg height is recorded when this signal equals zero. Cold productivity of leg is found from equation Q₀ = IU/2, where I and U are current and voltage drop across flexible bus additionally measured by microvoltmeter, respectively. Differential thermocouple used for running ΔT = f(I) curve at zero cold productivity is made in the form of three-layer switching wafer made of copper-constant-copper strips and placed between leg under investigation and reference specimen. Copper strips are connected through copper contact wires to compensating microvoltmeter.

EFFECT: ability of dispensing with measurements in legs already assembled in thermal cell; enhanced measurement accuracy.

1 cl, 2 dwg