A Calibrated Thermometer isn't nearly as expensive as a Fluke 87 and for that matter neither is a Fluke 87 that accurate:
Resistance
Maximum Resistance: 50 M?
Accuracy: Fluke 83 V: ±(0.4%+1)
Fluke 87 V: ±(0.2%+1)
Maximum Resolution: 0.1?
From the data sheet at this URL: <<Fluke 87V Industrial Multimeter | Fluke
And at $399.00 Much too Much overkill for an Arduino for it's other features and resources. Great accuracy requires many different things and the resistance measurement is just one.
An Arduino is capable of just that degree of accuracy however it requires some thinking first.
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