Expected variance of temp readings

[bighefty]

A couple of questions...

1) What scale of temp monitoring does everyone use? 1 sec, 1 min, 5 min, 10 min, etc?

2) What kind of variance should I expect to see?

Thanks,
Geoff

[JonW]

The answer is really dependent on what you're doing. If you're trying to monitor temp rise for a mash, you'll want to be on the faster scales. If you're monitoring fermentation or a kegerator, you'd want to look at it over longer periods.

Are you getting quick fluctuations? i.e. spiking up and down? If so, you need to attach a jumper from the BCS ground connection to an earth ground (AC wiring ground). This will stop the quick up/down fluctuations.

[bighefty]

The answer is really dependent on what you're doing. If you're trying to monitor temp rise for a mash, you'll want to be on the faster scales. If you're monitoring fermentation or a kegerator, you'd want to look at it over longer periods.

Are you getting quick fluctuations? i.e. spiking up and down? If so, you need to attach a jumper from the BCS ground connection to an earth ground (AC wiring ground). This will stop the quick up/down fluctuations.

That's the thing... I'm currently checking out a new freezer to use as a fermentation chamber. I have the temp probe in a glass of water. The BCS is grounded to the ground wire of my extension cord along with the relay board. I am getting temp spikes but I don't know if they are within reason.

I guess my main concern is not so much a temp swing but I don't want to be burning up the compressor motor. It doesn't appear to run more than 3 minutes every 40-45 minutes and doesn't appear to cycle on and off.

[JonW]

You don't say how much the temp spikes are, but they can't be that much if it only runs 3 minutes out of 45. For fermentation, I highly suggest using a thermowell dropped into the keg/carboy for monitoring the temp there.

[bighefty]

It depends.... If I watch the log while it updates every second, it seems to vary about .2-.3 degrees every second. I'm thinking that's well within what should be expected but I don't know.

[JonW]

For sure .2 to .3 is well within reason. You have no issues there.

Just to reiterate for fermentation though, a thermowell is best or even attaching the sensor to the carboy/keg will work. Using the glass or bottle of water will lag considerably behind where the temps are inside the fermenter.

[bighefty]

Understood....I will be using a thermowell inside the middle of the carboy.