Industrial commonly used in the thermal resistance of platinum thermal resistance, copper thermal resistance of two kinds. According to the provisions of IEC, the platinum thermal resistance has PT50 and PT100 two kinds of index number. Copper thermal resistance according to the WZC standard, the index number Cu50 and Cu100 two.
Measurement range:
PT50 for -200 ~ 650;
PT100 for -200 ~ 850;
Cu50 and Cu100 for -50 ~ 150 ten.
Nominal resistance value of 0 degrees C Ro:
Ro=50 Pt50;
Ro=100 Pt100,;
Ro=50 Cu50;
Ro=100 Cu100.
Verification of industrial thermal resistance should be carried out under what conditions?
Electric measuring equipment working environment temperature is 20 degrees Celsius + 2.
The indicating value of the electric measuring equipment shall be corrected, and the standard resistance should be given on the actual resistance value given by the certificate.
The heat resistance of the protective tube can be removed and put into a glass test tube (the test temperature is higher than 400 degrees Celsius), and the inner diameter of the test tube should be adapted to the temperature sensing element. In order to prevent air convection inside and outside the tube, nozzle using absorbent cotton (or high temperature materials) plugged tube insertion medium depth of not less than 300mm. Non detachable thermal resistance can be directly inserted into the medium.
The test, through the current thermal resistance should be less than 1mA.
Fifthly, measuring 100 DEG C, the resistance value, thermostatic bath temperature from 100 DEG C value should be no more than 2 degrees Celsius, temperature change per 10 min does not exceed 0.04 degrees.
Industrial thermal resistance temperature measurement error sources are mainly:
Dividing error;
The thermal effect error of resistance body;
External line resistance error;
The error caused by the heat exchange;
The dynamic error;
The matching error display instrument.
