remote temperature sensing

[Carl Lloyd]

I would like your thoughts on the best way to monitor/log remote
temperatures with a range of about 200 feet. I am working on a project that
will monitor my oil-fired furnace temperature and then also monitor the
differnent rooms of my home and have fun with it.

I've tried the LM34 but with the lengths of the runs I don't get reliable
results when I input the voltage into and ADC. What are your thoughts. How
is it usually done. I'm interfacing this all to an 8031.

Thank you , Carl

 

[William P. N. Smith]

"Carl Lloyd" <Lloyd@warwick.net> wrote:

I've tried the LM34 but with the lengths of the runs I don't get reliable
results when I input the voltage into and ADC. What are your thoughts. How
is it usually done. I'm interfacing this all to an 8031.

For long runs you might want to think about converting to 4-20mA
signalling, it's pretty easy to do and will give you much better
results. IIRC the LM34 app notes have a circuit, and all you need on
the receiving end is a resistor...