Reasons and solutions for explosion-proof thermistor faults

Explosion proof thermistor is a commonly used detection instrument with various advantages such as corrosion resistance, impact resistance, flexible use, and easy maintenance. It is widely used in multiple industries and can also be applied in flammable and explosive industries. Below are the reasons for the malfunction of explosion-proof thermal resistors and how to handle them:
Thermal resistance belongs to temperature measurement sensors and is also a primary measuring instrument. It is used in conjunction with wires and secondary display instruments to visually display the actual measured temperature value. It is normal for thermal resistors to malfunction after prolonged use, so it is necessary to master some basic methods to effectively handle these issues.
There are only two types of faults in the thermistor temperature sensor: short circuit and open circuit.
Judging these two states can be easily solved with a multimeter. For example, the resistance of the thermistor model PT100 or PT50 can be determined from its model. It indicates that the resistance value at zero is 100 or 50 Ω, respectively. At room temperature, the resistance value of the thermistor is higher than this value. Therefore, the resistance level of the multimeter is used to measure the resistance value of the thermistor. If it displays infinity, it indicates that the thermistor temperature sensor is open circuit. If it displays a resistance value below zero or close to zero, it can be judged as a short circuit. Mainly due to the slender resistance wire of the thermistor temperature sensor, these two states are prone to occur.
The fault phenomenon of explosion-proof thermistor is that the displayed value exceeds the range, the displayed value is too small, or the display is unstable.
The approximate direction of the fault caused by the display value exceeding the range is that there may be an open circuit state, a disconnection of the sensor or the entire wiring line, and loose wiring terminals. Check if the sensor is damaged, check if the wiring terminals of the sensor and the secondary instrument are loose, and check if the circuit is open or closed.
The approximate direction of the fault phenomenon of small or unstable display value, check whether there are small metal substances in the temperature sleeve, whether the temperature sleeve or wiring terminal has dust and liquid collection, and whether the wiring terminal has corrosion or dirty substances.
The displayed value becomes negative. Check for any wiring errors and for any short circuits in the sensor and wiring.
Two common troubleshooting methods for thermistor temperature sensors
If the sensor is short circuited, clean the sensor and its wiring terminals, and then dry the sensor. If it is a short circuit in the wiring, locate the circuit and resolve the fault. Also handle the wiring terminals of the secondary instrument. After processing, restore.
If the sensor is disconnected, it can be welded, but welding extends its resistance wire length, which has a significant impact on measurement accuracy. It can only be used after inspection. Therefore, it is still necessary to replace the thermal resistance temperature sensor, search for and restore the circuit breaker.
The use of secondary instruments, as temperature sensors generally use a three wire wiring system, be careful not to connect the wiring incorrectly. After the entire wiring is connected, the corresponding thermistor model must be selected for the secondary instrument, otherwise it will not be displayed.