Bimetallic thermometer to measure the temperature of the bearing?

Instrument recently received sales reflect problems, that there is a customer want to buy bearing temperature, bimetallic thermometer and bimetallic thermometer can measure the bearing temperature? Today is for everyone to introduce concrete by experiment, bimetallic thermometer bearing temperature measuring points touching, and for solid measured medium, bimetallic thermometer can be used to measure the bearing temperature? Average temperature instrument used to measure the object before the need for validation, can get the accurate data. Here is to verify the bimetallic thermometer can measure the bearing temperature. Before the experiment, the need for bimetallic thermometer calibration. Experimental method is: will be full of water heating electric kettle plugged in, make electric kettle of outside wall temperature gradually raised, find a thickness of 15 ~ 500 px plastic foam sponge clingy wall outside the electric kettle, This reduces the temperature loss, more close to actual situation) And on the plastic foam dig two holes close to the outer wall of electric kettle. The measurement end of bimetallic thermometer inserted in a hole in the head, make the bimetallic thermometer WenDuan top wall outside the electric kettle; Using standard platinum rhodium 10 & ndash; Platinum thermocouple ( S degree) As a standard, the standard platinum rhodium 10 & ndash; Platinum thermocouple WenDuan measurement is close to in the external walls of electric kettle, and fixed well, from plastic foam sponge lead arise out of a hole in the ice kettle. Can approximate to think outside of the bimetallic thermometer to measure electric kettle temperature and bearing temperature measurement at the same situation. After electrify, electric kettle outer wall temperature gradually raised, on the bimetallic thermometer and electronic potentiometer data respectively. Visible: (from the experimental data 1) Measured by the contact method, bimetallic thermometer income can't reflect the object being measured value for the actual temperature; ( 2) From the trend, bimetallic thermometer have delayed effect, can't reflect the temperature change in time; ( 3) Bimetallic thermometer is shown in value compared with the actual value difference is very big, such as the actual value is 84 ℃, the value of bimetallic thermometer for 46 ℃, difference is 38 ℃. Through the above experiments we can use a bimetallic thermometer to measure the bearing temperature, the indicated value and can not correctly reflect the real value of bearing temperature, therefore, cannot use bimetallic thermometer to measure the bearing temperature signal and provide high bearing temperature alarm and protection. So the bimetallic thermometer can not correctly reflect the temperature of the bearing.