# Math Range Error With NTC 100K Thermistor **URL:** \ **Category:** General Discussion\ **Created:** [March 28, 2023, 10:44pm UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507 "2023-03-28T22:44:56Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![arj3090](https://avatars.discourse-cdn.com/v4/letter/a/94ad74/32.png) [@arj3090](https://klipper.discourse.group/u/arj3090)\ **Post date:** [March 28, 2023, 10:44pm UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507/1 "2023-03-28T22:44:56Z")
### Basic Information: Printer Model: Troodon 2.0 MCU / Printerboard: Manta M8P `klippy.log` [klippy (1).zip](https://klipper.discourse.group/uploads/short-url/4D6nv7dh0wTtj7ZO3K8nHpAHZY8.zip) (2.8 MB) Math Range Error when using a 100K thermistor for the extruder and setting sensor\_type: NTC 100K MGB18-104F39050L32 When changing to below, the error goes away: sensor\_type : EPCOS 100K B57560G104F … ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [March 31, 2023, 5:44am UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507/2 "2023-03-31T05:44:16Z")
![image](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/1/100b1751ba063e52f95d094868c2e11f66b27467.png) You are printing a bit on the hot side. See [ADC out of range](https://klipper.discourse.group/t/adc-out-of-range/6643) ---
**Author:** ![arj3090](https://avatars.discourse-cdn.com/v4/letter/a/94ad74/32.png) [@arj3090](https://klipper.discourse.group/u/arj3090)\ **Post date:** [March 31, 2023, 11:04am UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507/3 "2023-03-31T11:04:45Z")
This problem arose when I had a bad thermistor. The original thermistor was a 1K. It started reading that unrealistic high temperature, so I changed it to the only thermistor I had which was the 100k ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [March 31, 2023, 12:29pm UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507/4 "2023-03-31T12:29:19Z")
Each temperature probe has certain characteristics. If you change it, you need to make sure to have the correct type specified or your readings will be crap. If you do not know the exact type (or the type is not explicitly listed here: [common-thermistors](https://www.klipper3d.org/Config_Reference.html#common-thermistors)) of a typical 100k NTC then use `Generic 3950` ---
**Author:** ![arj3090](https://avatars.discourse-cdn.com/v4/letter/a/94ad74/32.png) [@arj3090](https://klipper.discourse.group/u/arj3090)\ **Post date:** [March 31, 2023, 1:29pm UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507/5 "2023-03-31T13:29:15Z")
I was able to find the thermistor listed as a B3950, so I changed it to Generic 3950. Thanks, I totally missed the Generic 3950 type becuase I was only looking for 100k in the name. ---
**Author:** ![arj3090](https://avatars.discourse-cdn.com/v4/letter/a/94ad74/32.png) [@arj3090](https://klipper.discourse.group/u/arj3090)\ **Post date:** [March 31, 2023, 10:25pm UTC](https://klipper.discourse.group/t/math-range-error-with-ntc-100k-thermistor/7507/6 "2023-03-31T22:25:06Z")
Today I changed my hotend to a red lizard that says in the documentation that it has an NTC 100k thermistor. When I try both types of NTC 100k in the Klipper config, both give a math error in startup. I change it to the Generic 3950 and it works without error.