Common faults and treatment methods of WZP thermal resistance

WZP thermal resistance is used as a temperature measuring sensor and is usually used in conjunction with display instruments, recording instruments and electronic regulators. It can directly measure the surface temperature of liquids, vapors and gaseous media and solids in the range of -200 ° C ~ 420 ° C in various production processes. Since the thermal resistance has a certain service life, it is inevitable that a fault occurs, so it is very necessary to master the fault handling method.

The common faults and treatment methods of WZP thermal resistance are as follows:

1, thermal resistance open circuit

Check the disconnection part with a universal meter to determine whether it is a connecting wire or a thermal resistance open circuit. If the connecting wire is broken, it should be repaired or replaced.

2, the display value is infinite

The thermal resistance or the lead wire is broken and the terminal is loosened.

Treatment method: replace the resistor body, or solder and the wiring screw, etc.

3, thermal resistance short circuit

If the thermal resistance itself is short-circuited, it should be replaced. Check with a multimeter to determine the short-circuited part and repair or replace it.

Also, after the installation, the cover of the thermal resistance in a humid environment should be periodically opened, and the rust should be prevented so as not to be opened and cannot be maintained. According to the relationship between the temperature and the resistance of PT100, we should have a general formula of 0 degrees corresponding to 100 ohms, and an increase of 2.4 degrees for each ohm (for example: the temperature measured by 110 ohms is about 24 degrees, after When measuring with a multimeter, it can be judged whether the comparison is a problem of the thermal resistance itself).

4, the relationship between resistance and temperature has changed

Platinum resistance wire material is corroded and deteriorated

Treatment method: replace the thermal resistance wire

5, the display indicates that the value is lower than the actual value or the indication is unstable

The possible cause is water in the protective tube or metal shavings, dust, etc. in the junction box.

Treatment method: pour out water or eliminate dust, and dry the wet part to improve the insulation performance, but can not be fired.

6, the meter display value is zero or has a negative value

Display instrument and thermal resistance wiring is wrong, or thermal resistance short circuit

Treatment: Correct the wiring, or find the short circuit, strengthen the insulation