Thermistor Tuning?

[KAS]

Quick question regarding the thermistor temperature reading.

With the v2 stock hotend I made an excel chart of the different filaments I have and the temperature I used to print. Both on plain glass for PLA and diluted glue stick for ABS. (around 220c/70c for PLA)
When I switched to the E3D V6 and the .4 Nozzle, I noticed that I wasn't getting the same results in regards to bed adhesion. After a few PID autotunes nothing has changed except for the increased values I have to use for the hotend to make the filament stick.

I broke out the Fluke 1587 with thermocouple probe and stuck it directly on the heater and showed I was consistently getting 12c cooler temps than what the thermistor was picking up between various ranges from 200-240.


Question: Is it possible to offset this value to correct reading or is it just something I should live with and adjust my chart to the new values?

[Mac The Knife]

Yes, it can be adjusted. Somewhere on this forum it's described how.

[Polygonhell]

Badically you have two options, know the difference and live with it or mess with the firmware, if you decide to do the latter, it basically comes down to using a custom thermistor in the firmware and tweaking the beta value to get more accuracy in the temperature range you use.
John did post instructions somewhere, it's not very hard, but it does involve uploading firmware checking the readings, rinse and repeat.

[Mac The Knife]

http://forum.seemecnc.com/viewtopic.php?p=10259

[KAS]

Awesome, thank you all.