How to do an Ice bath or Boiling Water Calibration on the built-in meat thermometer or other thermometers

[CentralTexasClassic]

Hello,

Some people have been using boiling water to calibrate their Traeger meat probes due to it being closer to like a done brisket (200-210 internal). I have always struggled with the Traeger built-in thermometer not being the most accurate. So I first tried the boiling method with my thermapen on the stove using boiling water and noticed it kept saying 210.5 and I was worried my thermapen was out of its accuracy range of 0.5 deg F. After digging I found that in Austin where I live the boiling point of water is 210.6 deg F, so my thermapen was right and within range. Some advice for calibrating the Traeger to boiling water is to either cross-check with a known source (Thermapen, etc) or to use Thermoworks boiling point calculator to input your elevation and pressure of the day to get an accurate boiling value. Do not make the same mistake as me and assume water boils at 212 deg F everywhere.

For a few weeks, I was just adding 1.5 degrees to all the numbers my thermapen was reading out, but come to find out it was right all along. Which I should have assumed earlier on. Thermoworks also has some great resources on doing a proper ice test on all thermometers using crushed ice and making a "proper" ice bath. I do this to all my thermometers to validate their calibration.

Here is the link to that: https://www.thermoworks.com/thermapen101-creating-an-icebath/

I recommend doing the ice bath because if done properly the ice bath will be 32 deg F no matter your pressure or elevation. This is why it is an industry-standard for quick probe checks. I assume most people don't create the best ice bath and you can see large swings from 32 as seen in the last picture.

I do understand why you would want to do the calibration up towards the range of where your meat will be when done and try to eliminate the amount of error from opposite sides of the range. If you plan to do the boiling point method just figure out your boiling temperature based on local conditions and then proceed.

Citation: https://www.thermoworks.com/

 

[RayClem]

When doing the ice bath calibration, you want to be sure the contact area between the frozen ice and the liquid water is as large as possible. Crushed ice is ideal. Barring this, use a lot of small cubes. If you use an insulated container such as a double layer mug, it will be even more accurate.

If you want to use boiling water as a secondary calibration point, I would suggest using several thermometers to measure the temperature. Make sure none of the thermometers are allowed to tough the bottom of the pan as the temperature will be hotter there than elsewhere, As with the ice bath, for boiling water you need a large contact area between the liquid water and the gaseous water vapor. The will occur closer to the surface. The boiling point of water is only 212F/100C at standard sea level which is defined as 29.92 in mercury. If the actual atmospheric pressure is above or below this level as it frequently is even if you live on the seashore, the boiling point will vary. Thus, it is best to compare several thermometers and discard any outliers.