The temperature sensor is the one that was provided with DrDAQ, so I presume it must be the themistor.
The sonsor works without the extension, but as I add cable lengths, the answer becomes more strange. For example, with an additional 10 ft, the temperature is about 80 degress off, then with an extra 50 ft, the reading starts off fine, but every second gets higher, into the 100s, then finally off-scale, reading "****". It's almost as if there is some type of power/current limit being reached.
I agree, I would have thought the device has high impedence, so the long cable lengths would not be that much an issue, but it seems to be.
Does this make sense?