Re: MMIR X-10 Macro IR Module

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
news:YsSdnXodl4fobG7bnZ2dnUVZ_s-pnZ2d@xxxxxxxxxx
>
> Although thermistors are non-linear, aren't their outputs fairly
> repeatable?
> If I calibrate the output with a good digital thermometer, can't I always
> expect the output voltage to be the same for each calibration?   I would
> imagine I'd want to know where things like 32, 65, 68, 75 degrees F, and
> maybe a few others are at precisely, but I'm not sure I'd need anything
> else.  After all, it still doesn't get hot enough in the summer here for
> it
> to be lethal to get the outside temps wrong, unlike your area.  (-:

Yes, they are very repeatable, and you can actually calculate the voltage
for each temperature.  So it is possible to build a look-up chart.  I prefer
to just crank it through the formula to get degrees.  I log the daily
extremes, and temperature at sunrise.  I use those to control auxiliary
ventilation, and calculate the irrigation cycles we use during the summer.
Trying to grow anything in a few inches of soil on top of lava is tough.

Jeff