Temperature Probe Accuracy

Discussion of the physical aspects
berrywise
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Temperature Probe Accuracy

Post by berrywise »

I purchased all of my temperature probes from Electric Brewing Supply. I was curious if this is the kind of readings that are expected, with the probes having about a two-three degree swing from each other. In my test I used the three on the right, therminator, boil, rims probes.

Ice bath, all submerged at once in a large 64 ounce mason jar
https://youtu.be/7oaqi1mSg_c

Ambient temperature, sitting out on my workbench.
https://youtu.be/GLHX7GiO8B4

Thanks!
JonW
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Re: Temperature Probe Accuracy

Post by JonW »

Did you calibrate them?
berrywise
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Re: Temperature Probe Accuracy

Post by berrywise »

I never have, I believe I read that they came pre calibrated. That said I should note that my ice bath has too much water and not enough ice. I put another thermometer and it reads 42 degrees.
JonW
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Re: Temperature Probe Accuracy

Post by JonW »

The probes are fairly accurate, but if you want them all spot on, then you need to do the calibration yourself. This will generate unique coefficients for each probe.
Sparkologist
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Re: Temperature Probe Accuracy

Post by Sparkologist »

I am having the same problem.
I purchased the BCS 460 controller and (3) 1/2" MPT 4" BCS-460/462 Temperature Sensor with 8' wire lead. The three probes will eventually sync up but it takes about an hour after starting out nearly 10 degrees apart. Is there a way to shorten the response / sampling time? I will be using one of the probes for a rims element and I am concerned about the slow response time burning my wort.

Thank You
JonW
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Re: Temperature Probe Accuracy

Post by JonW »

When you talk about them "syncing up", are you measuring at air temperature? I ask because these probes are not ideal for measuring air as they actually do sample and respond very fast. Measuring air causes them to jump up/down a bit as air currents change. Simply hold the tip of one in your hand and you'll see how quickly it changes.

If you are getting varying temps with liquid, then you may want to calibrate the probes.
Sparkologist
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Re: Temperature Probe Accuracy

Post by Sparkologist »

I have performed this test several different times with different temperatures of water. I do not think it is a calibration issue as they all find a common temperature after half an hour or so. My main concern is scorching my wort, with a rims tube as they are so slow to respond.
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oakbarn
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Re: Temperature Probe Accuracy

Post by oakbarn »

How are they wired? Do you use a common Ground wire or "home run" the ground back to the BCS? Do you have splices in the Line? Is your wire twisted pair shielded?> I personally use 18 awg twisted pair to run to my probes and only have either a M12 disconnect or a single splice to connect to a fixed length cable. I found that I had an issue when I was using a single ground and then connecting that to the probes rather than a single twisted pair to the probe.
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Re: Temperature Probe Accuracy

Post by Sparkologist »

The wiring is simple. All three drain wires are terminated at the ground buss of my panel. I did use the the white as the ground and the black wires on the Temp1- Temp-2. There are no splices these are the 8' factory two wired shielded cables.
My next question: Is my controller learning? The reaction times keep coming down the longer I have them connected. It has been four days now and they are adjusting faster and more accurately.
Back to my first question: Is there any setting I can change in the controller for quicker sampling? Like I said I am concerned about the RIMS probe scorching the wort.

Thank you for your replies. I have very high hopes for this system and a good feeling about it.
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oakbarn
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Re: Temperature Probe Accuracy

Post by oakbarn »

You may not need the drain wires grounded. As far as I know, there is no "learning" for the Probes. Mine work great when I hook them up. I have mine with the M12 disconnects with 18 awg shielded wire run to a metal box with the female panel mount M12 then an M12 patch cable then the probe. I have checked them with a Thermopen and they are very accurate with no need to calibrate. I did buy the probes, patch cables and M12 females from Brewer's Hardware
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