List of thermistor types?

Twmaster

I've been searching the forums and the Internet a bit trying to find this.

Is there a table which lists each thermistor type and number for this firmware?

Thank you.

Repetier

In configuration.h you see the list. Also config tool offers the list of available thermistors. Better description of type si snot available. If you think yours is not listed, select in config tool user defined and an editor appears where you can simply define your curve from the temperature/resistance table in the datasheet.

Twmaster

Perhaps I'm missing something. I'm reading the configuration.h file and do not see a list of available thermistor types.

Further, while the configuration tool does list each type of thermistor it does not also list the corresponding type number as defined for use in the configuration.h file.

I have several different hot ends on swappable carriages for one of my printers. Being able to simply change the thermistor type number in the configuration.h file would be useful rather than have to rebuild the entire config from the configuration tool each time I wanted to make a change.

Thank you.

Repetier

It's only in the github version of configuration.h not in th eone generated by config tool. Here the relevant part

// What type of sensor is used? // 0 is no thermistor/temperature control // 1 is 100k thermistor (Epcos B57560G0107F000 - RepRap-Fab.org and many other) // 2 is 200k thermistor // 3 is mendel-parts thermistor (EPCOS G550) // 4 is 10k thermistor // 8 is ATC Semitec 104GT-2 // 12 is 100k RS thermistor 198-961 // 13 is PT100 for E3D/Ultimaker // 14 is 100K NTC 3950 // 15 DYZE DESIGN 500°C Thermistor // 16 is B3 innovations 500°C sensor // 5 is userdefined thermistor table 0 // 6 is userdefined thermistor table 1 // 7 is userdefined thermistor table 2 // 50 is userdefined thermistor table 0 for PTC thermistors // 51 is userdefined thermistor table 0 for PTC thermistors // 52 is userdefined thermistor table 0 for PTC thermistors // 60 is AD8494, AD8495, AD8496 or AD8497 (5mV/degC and 1/4 the price of AD595 but only MSOT_08 package) // 61 is AD8494, AD8495, AD8496 or AD8497 (5mV/degC and 1.25 Vref offset like adafruit breakout) // 97 Generic thermistor table 1 // 98 Generic thermistor table 2 // 99 Generic thermistor table 3 // 100 is AD595 // 101 is MAX6675 // 102 is MAX31855

Twmaster

Thank you that is exactly what I needed. I'm building a new printer and have a couple of different hot ends to test. Including the DyzEnd with 500C thermistor.

skwhite16

What happens if the parameter is set incorrectly, like if I am using a 100K NTC 3950 thermistor but have the parameter set to 8 for a ATC Semitec 104GT-2 thermistor? I would assume that the temperature control will be off (ex. inaccurate temp setting) but how drastic would the error be?

Repetier

Yes, it deviates a bit from real temperature. Not that any of them really measures the right temperature as temperature varies over position in nozzle.

The difference can be big. Nearly all have 100K at 25°C but the higher the temperature the bigger the differences. Especially if one sensor can handle 230 and one 500 the differences will be bigger.

If you are in the position to not know the type just select 100K NTC 3950 and see at which temperature extrusion work and use it. What you need is that the working temperature stays stable and that works at any temperature. Thy typical deviation is also why filaments say extruder temperature 180-210°C. It is a mix of real working range and added errors form the allowed deviance, place where you measure etc. So for every Filament you also need to test the best working temperature to print anyway. Only advantage of having the right type is you have more narrow range where to test.