Thermistor ADC calculation

knutselsmurf

I have a Mellow 450'C thermistor with these RT-table:

According the seller it's thermistor 66 in Marlin, tried that but it gives the wrong temperatures.. Same thing in the BLV (Duet-reprap), other settings..

For RepRap and Marlin we need some parameters like the ADC-values, the beta and more..

Can somebody explain how we can calculate this with this Mellow 450'C thermistor as example ?

(I want to use this thermistor on my Ender5 (Marlin) and on my BLV (Duet-Reprap)).

Veti

go to https://configtool.reprapfirmware.org/Heaters

click on a beta value, select custom.

and enter the values for 25, 180 and 300 degrees

Veti

also see
https://forum.duet3d.com/topic/19163/help-pid-tuning-dyzend-pro/47?_=1602843872701

dc42 says that that thermistor is not good for duet or marlin

Veti

also marlin thermistor 66 is
// R25 = 2.5 MOhm,

so its not that thermistor

Meltex

@knutselsmurf H!

Did you solve this issue? I have the same thermistor but cannot make it work right.

Veti

@Meltex
did you read dc42s post?

Meltex

@Veti yes. I understood that high impendance will not work and there must be 1M resistor in parallel. But I have already switched to regular 100K Epcos and do not want to play with thermistors again without any success that others achieved. Just curious.