Checking Therm Accuracy

[berrya]

I'm checking my Therm Pro's accuracy before my smoke tomorrow. They are showing about 25 degrees higher when checking with the oven temp (Oven Temp- 225... Therm-Pro-250... So I decided to bump the oven temp up and re-check.... (Oven Temp 250... Therm-Pro Showing 275)... However, when I checked with boiling water... they showed right at 212-213... Do you think my oven temp is just off?

 

[lovethemeats]

Yep. Bet it is. I know my oven is off at the lower temps until I get to about 360. Trust the boiling water. You have gas or electric?

 

[berrya]

It is a gas oven

 

[lovethemeats]

Yeah thats odd to be off 25 degrees. But I would trust in the boiling water test. Have a other meat probe on hand? To compare.

 

[lovethemeats]

Try the ice water test next with your unit. If it goes that low. Should get 32 on it. Your hitting 212 and 32. Heck. Your good. Oven off. Which is also good to know. Or. Where they just in a hot spot within your oven during the test. Could just be where you had the probes placed.

 

[johnmeyer]

I'm sure you know how to properly check the thermometer, but if you want some tips, I wrote about it a few months ago:

ET 732 Calibration

As already noted by others, ovens are often off by a LOT, especially gas ovens. I use three methods to check my oven temperature:

1. Oven thermometer. These are actually pretty accurate, but it matters where you place it in the oven. Also, it matters if the oven is full of food. I usually check with the oven empty, and I let the oven stabilize for at least fifteen minutes after it reaches the set temperature. I then take the first temperature reading, wait ten minutes and then do it again. I just did this four days ago while doing some cookies because I thought it was too cool, but the test showed it was dead on.

2. Point and shoot infrared thermometer. You just open the door, point at the oven wall, and push the button to take the temperature. These are pretty accurate, probably on par with the oven thermometer. You have to take the temperature immediately after opening the door because the oven walls will cool off pretty quickly.

3. Use your Thermapen (if you have one). These are individually calibrated at the factory and are as accurate as anything you are likely to find. To measure the oven temperature, I use my 2-ounce metal measuring cup and fill it with cooking oil. I then place that in the oven for one hour in order to get it to the same temperature as the oven. I then open the door, stick the Thermapen into the oil, and take the temperature. I like this method because the oil temperature will reflect the average temperature as the oven cycles up and down. Also, it uses the ultra-accurate Thermapen which is more accurate than anything I have, and most likely the most accurate thermometer most of us can buy.

I have a Thermador electric oven and it has a built-in calibration adjustment which I can set directly from the front panel. I check both ovens (it is a dual oven) at least once a year, and after twenty-three years, it still tests to within a few degrees of nominal, so I've never used the calibration, except to experiment to see how it worked. All ovens (including yours) can be adjusted, although for most people it is simpler, once you know if the oven is off, to simply set it to a higher or lower temperature. This is simpler because many older ovens must be partially disassembled to get at the adjustment.

 

[SonnyE]

Boiling water test is subjective to your altitude. So it may be low.
In plain Engrish, at my home water boils at 209 degrees.
I've proofed my thermometers, but find none are absolutely accurate.
The only real way is with a tested and certified thermowell. Otherwise, close is close enough.
I recently took 6 thermometers and tested them at the same time. A pan of ice water, which the 6 sensors were in, then took it to boiling slowly.
Some tracked closely to each other, one was running high.
Don't expect 'laboratory accuracy', unless you've paid for a certified instrument.

Maybe something here can help you test it, or adjust it to closer calibration. It's specific to your Therm Pro.