I was measuring in the chimney to check my calibrated thermometer against the meat probe. But I also tend to do most of my cooking on the top 2 racks. 25F-30F is a huge difference though - I could understand 5F or 10F degrees.
Now that I know the meat probe is accurate, I will place it next to the temperature sensor and test it that way.
I was also thinking that I like the idea of it running a little hot. Being able to get the MES40 up to 300F is something that I can see as beneficial....as long as it still can hold 225F. I may just calibrate the temp. sensor and live with it and simply make a calibration table. I would have 3 columns - set temperature, sensor level temp, chimney level temp.
I will post my results...
I think I arrived at the same conclusion...glad you posted this though - sometimes I am a bit slow haha
No problem, I'm glad the info helped :)
I have tried a ton of things to regulate temp within my MES40. This includes installing a convection fan, flipping the heating element, messing with a duct for the vent, heat baffles, a PID controller, etc. and I have come to the conclusion that you simply cannot get past the nature of the design.
Basically each rack will have a different temp. Even on the same rack you will have different temperatures from left, center, right positions.
I have been able to get quite a bit of consistency keeping temps the same or within the same ranges between racks as well as along the left, center, right positions of a single rack.
I have never been able to get things even between two racks or even across a single rack.
Every so often I even create situations where the smoker probe is blocked by meat or a pan and does not read temps properly. This is why I use 3 smoker probes so I can get the BEST range of readings I possibly can and when necessary I make adjustments to my set temp. For example the other day I set my foil pan and my smoker probe in a position where the smoker probe was reading 60 degrees lower then the other two probes. Once I noticed this situation I simply changed my set temp to hold according to what the backup probes were reading. Simple work around.
I have one final trick up my sleeve. I have a Birch wood board cut and ready to act as a shelf that helps trap heat underneath it. Smoke and air will be able to rise around it BUT my hope is that I can slow it enough to help trap heat under it. This way when I only use the bottom rack or bottom two racks that I can put this wooden shelf in to try and trap heat and keep it more consistent below the shelf.
The idea is that I have less wasted space to heat... I just need to get some whole chickens to do a test run with this idea. This is the last mod I can think of that I can do to try and help the temp consistency even more hahahaha.
Anyhow, best of luck and multi probe thermometers are your friend with the MES :)