B type thermocouple is a kind of very common type of precious metal thermocouple, people will often use to b type thermocouple. B type thermocouple for precious metals thermocouple. Accidentally wire diameter provision of 0. 5 mm, allowable deviation - 0. The positive (015 mm, 英国石油公司(bp) In the name of the chemical composition of platinum rhodium, contain the rhodium is 30%, platinum-based is 70%, the cathode ( bn) For platinum rhodium, rhodium for content 6%, therefore, commonly known as the dual platinum-rhodium thermocouple. The temperature is 1600 ℃, the long-term use of thermocouple short-term use temperature is 1800 ℃. B type thermocouple in the thermocouple series has high accuracy, stability, best measure [area wide, long service life, high temperature limit, etc. B type thermocouple for oxidation and inert atmosphere, can also be short term used in vacuum, but is not suitable for reducing atmosphere or containing metal or nonmetal steam atmosphere. B type thermocouple is an obvious advantage don't need a compensation for the compensation conductor, because in the range of 0 ~ 50 ℃ and internal potential less than 3 mu v. B type thermocouple deficiency is thermoelectric potential, thermoelectric potential rate is small, low sensitivity and mechanical strength under high temperature to drop, is sensitive to pollution, precious metal materials is expensive, and one-time investment is larger. B type thermocouple is actual index number for b double platinum rhodium thermocouple, it can measure of 0 ~ 1800 ℃ medium temperature, 1300 ~ 1600 ℃ can use for a long time. Is a better high temperature measurements thermocouple.