Equipment which employs the use of a thermistor may be under warranty. If you needed to replace a thermistor, it’s prudent to verify the expiration date of the warranty to ensure the new thermistor will be reliable for the duration of the warranty.

For example, suppose that the piece of equipment in question is a motor drive with a ten-year warranty that will go through on/off cycling 15 times in a shift, and will go through three shifts a day as illustrated below.


Product Life Example





To determine the life expectancy of the thermistor, you can perform an equation known as “MTBF” (mean time before failure of a thermistor. ) as demonstrated here.

Mean Time Before Failure







Ti = cycles to failure or time to failure prior to completion of the test
n = total # of samples tested
r = # of failures
t= duration of test