thermocouple automotive
Update:
The thermocouples described above all worked OK with two sets of circuits, in my embedded engine monitoring system, despite the sensor being grounded at the tip.
Four thermocouples were connected to a PIC processor via discrete amplifiers, and four were connected via the MAX6675 interface chips. I designed in both circuits not knowing which might perform better, but they both seem to work equally well, with the exception of some (not unexpected) scaling error on the discrete amp circuits.
I expected noise and a lot of "dithering" on the LCD readout but neither happened, happily.
To tweak accuracy I'm considering the purchase of a thermocouple simulator/calibrator. Can anyone advise what these instruments can do for me that I can't do with a low voltage source, a good voltmeter and a copy of the NIST tables?
Thanks in advance.