Up and running on the first try! and Probe question


 
B

Brent C

New member
Built my heatermeter 4.2.4 last friday night, and finished off the LCD and remaining components the next day. Wasn't able to test until I had received the RPi B which was yesterday.

I'm happy to say that she booted up on the first try, LCD screen lit up like a Xmas tree. BUT had no text, so I adjusted the pot, and voila! Although my first text did NOT show - no pit probe -. I had to configure the probe 0 for Thermocouple. Then it showed no pit probe, of which I'm waiting for the Thermocouple probe to arrive as well.

Anyhow I wanted to give Bryan a big thumbs up for shipping out the package very quickly, for excellent instructions on assembling the contraption, for continued support, and for being an enabler!

The sole question (for now, until I get more time to fiddle with servo/fan etc.), I have an existing thermistor probe. exactly this:

http://www.cdnw.com/product/replacement-temperature-probe-2

This was purchased as a replacement for my other digital thermometer. And wanted to know if this can be used? I unfortunately do not have any further specifications on the unit aside from what's in the PDF from the link above.

I did however, get OK ballpark ambient/body heat reading (didn't do crushed ice water, nor boiling water test on it yet), if I configure the preset to Maverick ET-732 AND resistor to 8kOhm instead of the predefined 10kOhm. I don't know what effects this setting will have over a larger temperature range. And since I don't have more detailed specifications on the probe, I didn't know what values to enter in if I had chose Custom instead.

if anyone has some experience with the CDW thermometer probes, I would very much appreciate any info.

Kind Regards,

Brent
 
Each thermistor make/model has its own temperature curve, unlike the linear readout from a thermocouple.

Don't change the 10K resistor option in the config, as it needs to match the resistor value on the HeaterMeter board, which happen to be 10K!

If you want to use that CDW probe, you'll need to plot its temperature/resistance values against a known probe such as a thermocouple or one of the other already supported probes listed in the config. From there you'll have to calculate the Steinhart-Hart values and then you'll be able to properly use the probe with the heatermeter.
 
Thanks for the quick Reply Steve... So in other words, just buy the recommended probes and be done with it!

should have jumped on the Maverick probes when they were 1/2 price and the Canadian dollar was closer to par.
 
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