Comparative Study on Platinum Vs. Palladium (PT/PD) Thermocouple Using Spherical Blackbody Furnace

Thermocouple is one of the most important and widely used temperature sensors in the research and industrial applications. Pt/Pd thermocouple is now a days becoming attraction of researchers to find its applications as a high temperature sensor. Investigation has been made, using tungsten strip lamp, a primary standard of non-contact thermometry, whose temperature correspondence was measured in terms of photoelectric current with the help of photoelectric linear pyrometer Photoelectric pyrometer has been used as a transfer standard for conferring the temperature of spherical blackbody furnace, which was used to measure the temperature of both Pt/Pd and type-S thermocouples in terms of their electromotive force by contact thermometry. Experimental results have shown the utmost linearity among two techniques used and also the advance characteristics of Pt/Pd thermocouple over type-S thermocouple in a high temperature range from 800 °C to 1300 °C. The uncertainty in the comparison from various sources was found to be within ±1.4 °C.