In domestic thermoelectric thermometers at their graduation resistance of a chain, external concerning a millivoltmetr, i.e. wires and the thermocouple (Rpr + RTP), equal 5 Ohms is considered. Adjustment of resistance of this external chain by means of the additional coil of resistance from a manganin directly at installation of the device.
If for the applied PTR coefficients And and are not known In, but resistance of R1 and R2 are known at Θ1 and Θ2, the size of resistance and coefficient In for any other temperature can be determined from ratios
Tungsten and tantalum have high TKS, but at a temperature over 400 °C they are oxidized and cannot be applied. For low-temperature measurements well proved some phosphorous bronze. Besides, for measurements of low temperatures indium, germanic and coal thermoresistors find application.