I am with eman on this one. I also don't know what your going for (turning the unit off once it reach the foods desired temp). But i set the timer and that works in the same manor. Maybe your looking at doing some long term smokes and didn't what your MES running when the food reaches the desired temp. I have done some long smokes and i always check temps and add chips every hour to ensue everything is running good. The MES is kinda like a set it and forget it but i still monitor every thing hour by hour.If you have a MES w/ digital read out it cycles the element when it reaches the set temp or shuts off the power when it runs out the clock.
I think that the best thing for you to do is, Once you figure out your smoking times set the timer for as close to the figured time as you feel comfortable with.
Don't know what you are trying to achieve, But The big thing is once you figure out how to turn it off ,
MAKE SURE the temp. of the meat does not drop below 140 degrees before you can get to it.