# Specific 3D Printers, Scanners, & Hardware > RepRap Format Printer Forum >  Electronics problem: Thermocouple reading on RAMPS 1.4

## Osama Kamal

Hi there RepRappers  :Smile: 
it looks like I've bought an MK8 extruder for my 3D printer but I found that the temperature sensor is a thermocouple and not a thermistor !!
my electronics are:
Arduino Mega 2560
RAMPS 1.4
I figured out that RAMPS 1.4 doesn't read thermocouple !! 
does this problem have a solution ??
NOTE: I use sprinter and repetier firmwares.
SAM_0134.jpg

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## jimc

sure get a thermistor and either mount it in the block if there is a hole for it. if not and even a more accurate way is to take 1/4" kapton and tape it to the side of the nozzle. wrap the kapton tight. i use marlin and it has a PID auto tune feature. if your firmware has that then run it.

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## Osama Kamal

that's not what I meant, I meant that RAMPS 1.4 doesn't read from a thermocouple !! ... but I searched for it and found that it needs an extra module "thermocouple amplifier".
the most famous are AD595 op-amp circuit and MAX xxx something !!
I will build my own amplifier and connect it between my thermocouple and RAMPS 1.4
I found solutions there:
solution  :Smile: 
reference RepRap Wiki

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## BlackDragon

You're both right.

If you want to use the thermocouple, you'll need the amplifier to bring the signal up to a stable and readable level.
If you don't want to deal with the extra circuitry, though, you can certainly leave the thermocouple disconnected and install a thermistor, for standard operation.

Personally, I don't have the experience with 3D printers to make a call on this, but from an electronics standpoint, the fewer circuits and signal modifiers you have, then easier it is to setup and troubleshoot.

I don't recognize your printhead, so I'm not familiar with the layout.  Would it be possible to remove the thermocouple and install a thermistor in its place?

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