When testing, use the ohm gear of the multimeter (depending on the nominal resistance value to determine the gear, generally R1 gear), which can be operated in two steps: first, test at normal temperature (indoor temperature is close to 25 degree ), use alligator clips instead of test pens to clip them separately. Measure the actual resistance value of the two pins of the PTC thermistor, and compare it with the nominal resistance value. If the difference between the two is within ±2Ω, it is normal. If the actual resistance value is too different from the nominal resistance value, it means that its performance is poor or damaged. Secondly, heating test, on the basis of normal temperature test, the second step test - heating test can be carried out, a heat source (such as an electric soldering iron) is heated close to the thermistor, and the multi-function indicator is observed. It is seen that the multi-function indicator changes with the increase of temperature, which indicates that the resistance value is gradually changing (the NTC resistance value of the negative temperature coefficient thermistor will become smaller, and the PTC resistance value of the positive temperature coefficient thermistor will become larger) , When the resistance value changes to a certain value, the displayed data will gradually stabilize, indicating that the thermistor is normal. If the resistance value does not change, it indicates that its performance has deteriorated and cannot be used continuously.
Sljedeće točke treba imati na umu tijekom ispitivanja: (1) Rt mjeri proizvođač kada je temperatura okoline 25 stupnjeva, pa kada se mjeri Rt multimetrom, treba ga izvesti i kada je temperatura okoline blizu 25 stupnjeva do osigurati provjerljivost. pouzdanost. (2) Mjerna snaga ne smije prelaziti navedenu vrijednost kako bi se izbjegle pogreške mjerenja uzrokovane toplinskim učinkom struje. (3) Obratite pažnju na pravilan rad. Prilikom testiranja, nemojte štipati tijelo termistora rukama kako biste spriječili da temperatura ljudskog tijela utječe na test. (4) Pazite da izvor topline i PTC termistor ne budu preblizu ili izravno u kontaktu s termistorom kako biste spriječili opekotine.
