Temperature probes let us know the exact temperature at various points inside the roaster while we are roasting. We find it crucial to use thin probes that react instantly to show us exact temperatures.
There are different types of probes, the most important temperature probes are in the drum and at the airflow point out. The drum temperature probe typically sits on the front panel of the drum. It is important to place the temperature probe so that it sits in the mass of the beans when they spin. This is usually off centre in the lower left or right of the drum where we can measure the most representative temperature of the beans, and avoid only measuring the air pockets in the drum - especially when running smaller batch sizes.
The position of our drum probe on our old UG15 roaster