Hotend and build surface temperature calibration

Tools needed:
Thermocouple k type or similar temperature meter. (calibrated to 100c boiling water)
(do not use infared, or laser type thermometers, these are inaccurate for this purpose)

this is what I use for temperature calibration. http://www.amprobe.com/amprobe/usen/HVAC-Tools/Thermocouple-Thermometers/TMD-50.htm?PID=73400



The procedure is fairly simple and is valuable in making the correct temperature setting of your hot end for prints. The best way to do this is before you feed the filament through your hot end.

I will be using the thermocouple sensor placed inside the hot end, pushed all the way down to the tip of the nozzle.

Heat up your hot end to operating temperature and note the thermocouple meter reading, continue doing this for a couple more sets of temperatures. For example: 180c, 190c, 210c, 220c (note: if your temperatures are way off, do not go above 240c, keep an eye on your thermocouple meter reading as you adjust temperatures)

You will find that, if you have a temperature variation, it will be consistant throughout the selected test temps. This variation will be what you need to factor in to set your temperature in rephost.

So say you have temperature variation of +10c, in order for your hotend to be at 220c, you would set the temperature to 210. This is considered your calibrated temp.

I have included below what my numbers were and to show an example of my temperature calibration. In my printer my hotend temps were off +6c and my bed temperature -3c.


Note: preferred that you already have done the pid autotune routine for your hot end and build surface completed (if you have a heated bed). If you do not know how to do this, see my other thread.
If your temperature graph in rephost is not linear, then a pid autotune will dial it in better. What you want to see is a smooth straight line once you have reached set temperature on the graph.