Why platinum-rhodium thermocouple has such a strong advantage

Actually platinum-rhodium thermocouple belongs to the thermocouple of precious metals, of all the series, the thermocouple with the measurement accuracy, platinum, rhodium thermocouple temperature range of the temperature measurement of relatively wide, measurement of stable performance, upper limit of temperature is very high, and the advantages of long service life and suitable for use in a inert and oxidizing atmosphere, of course, also can be used in a short period of time in a vacuum, but is not suitable for use in a contain metal, nonmetal and reducing atmosphere, platinum, rhodium thermocouple is another advantage of the wires do not need to use the compensation to compensate, but the shortcoming is the thermoelectric potential, because of platinum-rhodium thermocouple thermoelectric potential rate is relatively small, and the sensitivity is relatively low, if is used at high temperature, mechanical strength will be decreased, so the pollution can be very sensitive, because of the precious metal materials is very expensive, so the one-time investment will be relatively large.

and the inner core of platinum-rhodium thermocouple basically is the use of the precious metal platinum-rhodium wires, has the very strong stability and antioxidant performance, the precision is very high, measurement results of measuring and comparing the advantages of accurate and very high temperature resistant, platinum, rhodium thermocouple in the hot electric will change by measuring the temperature change, and it is only the size of the can and thermocouple materials and the temperature on both sides of the relationship, so it doesn't matter and the diameter of the hot electrode length, platinum, rhodium thermocouple will change the shape of the external because of the use requirements, but its internal structure, under normal circumstances is by protecting tube, thermal insulation sleeve electrodes and wiring box, etc.