Faulty temperature reading dyze PT100 temperature sensor
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Hi all,
I in my setup I use a temperature sensor from dyze design "(https://dyzedesign.com/shop/accessories/pt100-temperature-sensor-2/) in combination with the duet PT100 daughter board https://reprapworld.nl/products/elektronica/duet3d/duet3d_pt100_dochterbord_voor_duet/?f=gs&f=gs&mkwid=sjLTzh2Ni_dc|pcrid|301315843193|pkw||pmt||slid||prid|1835&pgrid=58873543863&ptaid=aud-393449453680:pla-296303633664&gclid=CjwKCAiAsaOBBhA4EiwAo0_AnBxHJtcMnphw3kXYygT7jeHICZcpqpKWrRIYcuaMbR6UNsz_4gclgRoCZnIQAvD_BwE
I chose these options as it seemed that it would gave me the best precision and I really like the M5 thread as I make my own hot ends witch than can be easily changed.
However, at room temperature the sensor gives a reading that is 7 degrees above the actual temperature (based on the bed thermistor and the temperature sensor in my room.
it does this when connected to my hot end with a lot of wiring in-between but when minimilize the wiring in between it stays the same..
Is there a setting I should change?
Sincerely,
Max -
Assuming that the sensor is good, a reading 7C too high means you have about 3 ohms resistance in the wiring between the sensor and the PT100 daughter board. You have a couple of options:
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Change the wiring and connectors between the sensor and the daughter board to have lower resistance. Each ohm of resistance will increase the reading by about 2.5C.
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Close to the sensor, change to a 4-wire connection and run those 4 wires back to the PT100 board. See section "Hot end wiring" at https://miscsolutions.wordpress.com/2016/06/25/more-delta-printer-upgrades-wifi-and-silence/ for an example.
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Thanks for your fast reply. I have not yet been able to try to use the 4 wires solution. However, I think it is not in the cables, but maybe a faulty sensor / daughter board as it also showed a wrong measurement if I plug in the sensor directly in the daughter board without the wiring that I use in my end setup.
I was also wondering if there is a way to just subtract 7 of the value the screen displays.
Sincerly,
Max -
@Tricep-terry, if you connect the 100 ohm resistor supplied with the daughter board to the two middle places of the terminal block in place of the sensor, what reading do you get?
