Reliable NTC Temperature Sensor for Freezer Trailer

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Reliable NTC Temperature Sensor for Freezer Trailer


Imagined high quality overseas fresh food served on you dining table, for example, Norwegian salmon, cherries from Chile, they are all stored in freezer trailers equipped with NTC temperature sensors and delivered by cold chain transport at safe and consistent temperature.

freezer trailer temperature sensor
Reliable NTC temperature sensor for freezer trailer

The freezer trailer, also called the refrigerated trailer/ reefer trailer, it is one of the most essential types of cargo trailers in modern cold chain logistics. Let’s take a closer look at its refrigeration and temperature monitoring system, we can find a tiny small piece of component made of a long black cable and a metal ring lug probe.

What is an NTC temperature sensor?

The small tiny component above is NTC temperature sensor. It is made of an NTC thermistor, a thermal sensor operates with decreased resistance when temperature increasing. EXSENSE has its own R&D capability and manufacture our NTC chips as well as NTC thermistor. Based on specific requirements of cold chain freezer trailer, the NTC thermistor will be connected to a Teflon insulated cable and potted in to a metal probe by epoxy.

How is the NTC temperature sensor designed?

  1. Housing/probe: brass with nickle plated
  2. Thermistor: R25=10KΩ±1% , B(25/50)=4100K±1%
  3. Epoxy: black
  4. Cable: UL10362#26AWG *1C Black

Reliability test

  1. High temp test: 200±5℃ in air for 1000 hrs
  2. Low temp test: -40±5℃ in air for 1000 hrs
  3. Temperature cycle: -30℃×30 mins→Room temp.×10 mins→100℃×30 mins of 10 cycles
  4. Charge test: Charge DC 0.2mA for 1000 hrs at normal temp. and normal humidity.
  5. Lead wire strength tensile: Apply 20N force to the lead wire for 1 min
  6. Drop test: Drop it onto concrete floor from 1 meter height