Digital Thermometer Question - Different Reading using different probes

[zx24]

I have two digital thermometers, one has worked well for me and the other is a little cheaper and used as a backup. I hooked up my good thermometer (wireless) and it wouldn't sync. So I took out my back up thermometer and connected the probe from my good thermometer to back thermometer display and it worked. This morning I decided to put the other probe in the meat as well and it is giving me a different reading. Based on the readings below, should I just trust the old probe and thermometer? I am smoking a pork butt to 205. Should digital probes work well together if they are a different brand?

New probe + Old display = 183 degrees

Old probe + Old Display = 159 degrees

Analog meat thermometer = ~153 degrees

 

[5oclocksomewher]

Test in boiling water. Should read 212.

 

[zx24]

I was able to get the good thermometer synced and both were reading within 2 degrees of each other. I guess using a different probe will impact the results.

 

[venture]

A different brand probe can be a problem.

Also, a hot water test for all?  212 at sea level.  Adjustments needed for higher altitudes.

Good luck and good smoking.

 

[oldschoolbbq]

As stated , do boil test and record the temp. @ a rolling boil for each of the therms. and use those readings as your guide ( denote #1 and #2 for each therm. so you don't get mixed up;)-

 

[zx24]

Thanks, I will try the boiling water test.