A primary design goal in creation of the Z-Temp was accuracy. There are already plenty of potential error sources in the printer itself, and we want the Z-Temp to add as little further uncertainty as possible. The Z-Temp's specifications attest to our success in this regard.
The block diagram below shows the major error sources in the system:
Note that the ColorTemp™ visual thermometer is separate from the Z-Temp offset and motherboard circuitry and therefore displays the extruder temperature to within a maximum of ±5ºC of actual regardless of error sources elsewhere.
The Z-Temp's Temperature Monitor Output voltage is as accurate as the thermocouple and its signal conditioning circuitry. Errors in the thermocouple and conditioning circuitry cannot be quantified without high-accuracy laboratory temperature measurement equipment to measure the actual hotend temperature.
The accuracy of the M200's motherboard measurement electronics is unknown and depends on the accuracy of its reference and the resolution of its A-D converter. Errors in the motherboard measurement will manifest themselves as deviation from the nominal software setpoint.