Jun. 03, 2021
Thermistor is a type of sensitive components.Based onthe temperature coefficient, thermistorsaredivided into positive temperature coefficient thermistor (PTC) and negative temperature coefficient thermistor (NTC). In this article, we'll talk about how to verify the resistance of thermistors at different temperatures.
The alleged resistance of a thermistor is measured with a special instrument at a temperature of 25 degrees Celsius. Under normal conditions, it can also be checked with a multimeter. However, when using a multimeter, a thermal effect is formed due to the large working current, which often causes the measured value to be inconsistent with the alleged resistance value. If only the resistance of the thermistor is required to be measured to determine its type and whether it can work normally, a multimeter can be used to check in the following methods:
Room Temperature Check:
Set the multimeter to the ohmmeter, and let the two test leads touch the two pins of the thermistor. The reading of the multimeter is the resistance value of the thermistor at room temperature. Under the premise of correct selection of ohmmeter, if the reading is zero or infinity, it indicates that the thermistor has been damaged.
High Temperature Check:
Put an electric soldering iron close to the thermistor. If the resistance displayed by the multimeter has changed from normal temperature resistance value and returned to the normal temperature resistance value when the electric soldering iron is moved away, then the thermistor is still effective.
Low Temperature Check:
Clamp the two pins of the thermistor with a multimeter clamp, and put the thermistor into the refrigerator. Normally, for negative temperature coefficientthermistor, the resistance value displayed by the multimeter is larger than the resistance value at room temperature; for positive temperature coefficientthermistor, the resistance value displayed by the multimeter is lower than the resistance value at room temperature.
Hopefully the above checking methods are useful to you. It is advisable to choose regular manufacturers when purchasing thermistors so that the product quality is guaranteed.
Dongguan Zhixu Electronics Co,. Ltd (JYH HSU(JEC)) manufactures a full range of high quality thermistors of competitive price. JEC is ISO9001 and ISO14001 certified. JEC's safety capacitors (X and Y series) and varistors have passed certification of main industrial countries across the world. JEC’s ceramic capacitors and film capacitors are in line with environmental protection directives.