Ambient temp probe placement

[oregonrider]

I've had a GMG (Green Mountain Grill) for years. It's the Daniel Boone model.
I also have a Thermoworks Signals WiFi thermometer, which comes with an ambient probe thermometer.
I could never get the ambient probe to read even close to what the GMG temp is set to so I just gave up on using the Thermoworks for ambient temp (I still use the meat probes).
Well, today I have a brisket on and I need to know if the smoker fails for some reason and the ambient temp drops so, I'm at it again.
I put the ambient probe near the brisket and set the GMG to 200. The Thermoworks reads 30 - 60 degrees higher.
1. If you use ambient probes in your pellet smokers, where do you place the probe?
2. Who do I trust? The GMG or the Thermoworks.
The GMG app has a place where I can adjust the smoker's reading / setting but I hesitate to do that without some other calibration instrument.
Here's a graph from the Tworks app.

 

[schlotz]

Hmm, definitely an amount of temp swing there but nothing I'd fret over. Personally I would place the TWorks amb probe a bit away vs directly next to the brisket just to not have evaporation play a part in the readings. Of course once the stall has taken place that becomes less of an issue. TWorks products are calibrated so I would stick that one. You can verify the probe accuracy using ice water and boiling water.

 

[SmokinEdge]

Place the ambient probe grate level next to the meat. Trust the thermoworks over the GMG probe, none of the manufacturers probes are accurate, sad really.

 

[thirdeye]

I put my pit probe a few inches above my meat. I rarely use a meat probe on the larger barbecue cuts of meat.

 

[Randy1]

Pellet grills have the flaw of a small heat source. The grill Heat deflectors help but they are not perfect. Same problem with a wood burner but the temperature spread is a bit broader.
A well placed water pan will help a great deal.
In addition up, and down in a pit makes a big difference in temperature. Thee higher the hotter.

In my OJ's rider dlx I put a probe in that is higher in the pit than the stock one.