Temperatur offset

Topenga

Hello together,

I have a significant difference between Nozzle and heated bed temperatures when heaters are off.
Is there a possibility to measure the real temperatures and to adjust the offset somehow?
Does that makes sense? I struggle that the real temperatures are quite to low....

Here my config:

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B4138 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0 ; map heated bed to heater 0
M143 H0 S110 ; set temperature limit for heater 0 to 110C

M308 S1 P"spi.cs1" Y"rtd-max31865" ; configure sensor 1 as thermocouple via CS pin spi.cs1
M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M143 H1 S350 ; set temperature limit for heater 1 to 350C

Many thanks in advance

Danijel T.

cosmowave

@topenga said in Temperatur offset:

I have a significant difference between Nozzle and heated bed temperatures when heaters are off.

How big is the difference?

Topenga

@cosmowave said in Temperatur offset:

@topenga said in Temperatur offset:

I have a significant difference between Nozzle and heated bed temperatures when heaters are off.

How big is the difference?

Hello,

The difference is between 8 and 10 degrees.

Thx

dc42

@topenga see https://duet3d.dozuki.com/Wiki/Calibrating_thermistor_and_PT1000_readings. Your PT100 reading should be accurate, unless you are using a 2-wire connection and you have significant resistance in the cable to the PT100 (in which case it will read 1C high for every 0.4 ohms of resistance); but you may need to calibrate the bed thermistor input.

Topenga

@dc42 said in Temperatur offset:

@topenga see https://duet3d.dozuki.com/Wiki/Calibrating_thermistor_and_PT1000_readings. Your PT100 reading should be accurate, unless you are using a 2-wire connection and you have significant resistance in the cable to the PT100 (in which case it will read 1C high for every 0.4 ohms of resistance); but you may need to calibrate the bed thermistor input.

Hello DC42,

Thanks for answer.... Will try and return the outcome!

Danijel T.