Thermocouple measurement range

[charlespax]

With a thermocouple disconnected from Electronics version 0.1 at the the terminal I'm getting the following outout

> Cold junction temperature: 27.875 C
> ADC voltage reading:       255.998 mV
> Thermocouple temperature:  999.000 C

Does this mean the absolute maximum measurable temperature is 999 C? If so, we don't support K-type thermocouples (https://github.com/PaxInstruments/t100-electronics/issues/24).

Whats the story here?

[kehribar]

999C is just an arbitrary number that I put (https://github.com/PaxInstruments/t100-software/blob/master/commandline/t100_lib/t100_lib.cpp#L277) without looking at the exact limits of the range.

We are using these coefficients: https://github.com/PaxInstruments/t100-software/blob/master/docs/allcoeff.txt#L299 and they have a range of -270 to 1320 celcius.(https://github.com/PaxInstruments/t100-software/blob/master/docs/allcoeff.txt#L244)

I should create a much bigger "error" return for out of the range situations and more importantly I shouldn't show any temperature value to the end user at these times.

[charlespax]

Okay good. I was worried for a moment :-)

For the T400 we're using four dashes as described in the manual. We should probably stick with the same thing unless there is a compelling reason to do otherwise. We discussed this same topic for the T400:

• LCD: Display indicates disconnected thermocouple
• Serial: Data string indicates disconnected thermocouple

[charlespax]

Closing this because it's not a bug. Moving implementation to https://github.com/PaxInstruments/t100-firmware/issues/10.