🚀 go-pugleaf

"Antony N. Lord" <antony_lordX@hotmail.com> writes:


>>   Actually, the LM35 and variants are more accurate than most commercial
>> thermometers; one has to shell out a fairly good chunk of change to get
>> a calibrated thermometer as good as or better than these ICs.
>>   No calculations, lines of best fit, or any other trash like that.

>I suppose that is true - but surely there has to be calculations / 
>adjustments made due to voltage loss etc. in the cable run between the 
>sensor and the interface.

>More importantly - any clue as to bringing the maximum output voltage 
>(at the upper measuring temperature point) closer to the 4095mV level.

>It seems pointless not to be using the "full scale" of the input board.


I'm snowed in/out {in at a friend's, out of BWI..} but thinking out
loud... the LM35 spec sheet had a suggestion of a ?200 ohm resistor
at the device, getting you a current loop scheme.  Could you then
use a 2K resistor across the DVM input; getting you 0.1v/C?

The depressed zero is harder; ISTM there are schemes on the sheet
with split supplies. 
	Or
Are you wed to the LM35? I seem to recall similar sensors that 0K,
not 0C based, getting you 2730mv at 0C.


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