Inkbird Calibration

[jayk34]

Had a search on the forum but didn't find a definitive answer on this.

I bought a second inkbird 308 WiFi to use in my second fermentation fridge. I decided to calibrate it this morning. I boiled a kettle of water and let it cool for a few minutes. I used my 2 calibrated thermometers which were reading the same value 91.5 but the inkbird was reporting 89.1 (2.4°C) too low. This continued into the 80's. I thought job done and set the calibration temperature to 2.4°C in the app so that it matched the 2 calibrated thermometers.

I now tested tap water 7.9°C on 2 thermometers but the inkbird was showing 10.3 because of the calibration offset. That means at lower temperatures the inkbird is accurate and doesn't need the calibration. I only tested teens, 20's and 30's and the inkbird was correct which is more than sufficient for for fermentation temperature.

Anyone know if Is this normal for the inkbirds? I see @Hazelwood Brewery you use it to control boiler at mash temperatures. Does yours require calibration offset at those temps ?

 

[Hazelwood Brewery]

I believe I’ve checked this before and found it accurate but will check next time I do a brew - it won’t be long!

 

[peebee]

It's a "single point" calibration, every thing either side of that point supposedly varies according to a "linear" or "straight-line" relationship (which it probably doesn't, but is considered "near enough"). So calibrate it to a temperature near to the temperature where you'll be using it (say 20C). and enter the difference in the "CA" setup step (press "SET" for about 3 seconds, then press "SET" about 6 times to get to the "CA" setting - don't forget to press and hold "SET" for another 3 seconds to exit and save the setting).

This is where platinum (PT100) probes are considered so "good". They measure with a more accurate "linear" relationship.

 

[jayk34]

It's a "single point" calibration, every thing either side of that point supposedly varies according to a "linear" or "straight-line" relationship (which it probably doesn't, but is considered "near enough"). So calibrate it to a temperature near to the temperature where you'll be using it (say 20C). and enter the difference in the "CA" setup step (press "SET" for about 3 seconds, then press "SET" about 6 times to get to the "CA" setting - don't forget to press and hold "SET" for another 3 seconds to exit and save the setting).

This is where platinum (PT100) probes are considered so "good". They measure with a more accurate "linear" relationship.

Yeah, I have it calibrated for fermentation temperature range for ales 19°C- 23°C which means that the calibration setting is 0. Will check it some other time is I need it for mashing temps.

Was just wondering if they are all the same. Can't check my other one as it's currently in use.

 

[peebee]

So you have it measuring okay around "19°C- 23°C" with "CA" set at zero. But at 91.5°C it under-measures by about 2.4°C?

That's just the way it is!

And if they were all the same, why do they do they bother giving a setting ("CA") to alter the calibration?

You just have to accept it's "near enough" (or pay a small fortune for something better).

 

[jayk34]