Common first step: measure the nominal resistance at room temperature (about 25°C). Select the appropriate ohm gear according to the nominal resistance value. The nominal resistance value of the thermistor resistor in the picture is 5Ω, so the gear is RX1 gear, and the red and black test pens are respectively contacted with the two electrodes of the thermistor, as above As shown in the picture, then check the measured resistance value on the dial.
If the resistance value is consistent with or close to the nominal resistance value, it means that the thermistor resistor is normal.
If the resistance value is 0, the thermistor is shorted.
If the resistance is infinite, it means the thermistor is open.
If the deviation between the resistance value and the nominal resistance value is too large, it means that the performance of the thermistor is deteriorated or damaged.
The second step can change the temperature measurement resistance. Use the flame to get close to the thermistor (do not let the flame touch the resistor, so as not to burn the resistor, as shown in the picture above, let the heat of the flame heat the thermistor, and then touch the red and black test leads to the thermistor respectively. one electrode, and then check the measured resistance value on the dial!)
If the resistance value changes compared with the nominal resistance value, it means that the thermistor is normal.
If the resistance value changes in the direction greater than the nominal resistance value, it means that the thermistor resistor is PTC.
If the resistance value changes in the direction smaller than the nominal resistance value, it means that the thermistor resistor is NTC.
If the resistance does not change, the thermistor is damaged.
