An overview of platinum-rhodium thermocouple

So-called platinum-rhodium thermocouple, can also be called S type thermocouple, this product really belongs to a kind of precious metals thermocouple. One for the product I the rules of the wire diameter of 0. 5 mm, the scope of allowable deviation for - 0. 015mm。 One of the positive chemical composition for the platinum rhodium, rhodium element content is 10%, platinum content is 90%.

compared to other types of thermocouple products, this type of thermocouple has many advantages. This platinum rhodium thermocouple long-term use temperature is about 1300 ℃, and in a short time, the use of the temperature as high as 1600 ℃. In addition, its accuracy is very high, at the same time, also has a good stability.

users in the use of the platinum-rhodium thermocouple products, will also look at its wide temperature range, under normal circumstances, can keep long life. In addition, to determine whether from physics or chemistry, its performance is in a good state.

so, not only with the thermoelectric potential and oxidation resistance of outstanding advantages, platinum, rhodium thermocouple is often used in the oxidation and inert atmosphere. Precisely because it has so many excellent properties, so for a long time for the international temperature scale interpolation instruments, is very the attention, 'he said.

of course, this kind of platinum-rhodium thermocouple also has some disadvantages, the shortcoming of the main performance is: in the condition of high temperature, its mechanical strength decreased obviously; Thermoelectric potential rate is smaller; Sensitivity is low; Is sensitive to pollution; Material is expensive, investment cost is higher.

in addition, actually this kind of platinum-rhodium thermocouple under the condition of different temperature, its measurement precision is not the same, usually in the normal use for a long time at about 800 ~ 1300 ℃ temperature measurement accuracy, and when the temperature at 800 ℃, the platinum rhodium thermocouple temperature measurement accuracy will be reduced.