Log Data

With QPID's control algorithm now running quite nicely, I logged data during a recent rib smoking to see just how good it is. Weather conditions were cool and windy, so it was a good test for the system.

The plot shows that the actual temperature (red) stays within 2 degrees of the target temperature (blue), which is way better than I could ever hope to do adjusting the dampers by hand. The green line shows how the fan speed adjusts to maintain the desired temperature.

The yellow line shows the average fan utilization gradually increasing as the fuel is consumed. The QPID software monitors this value and sends an alert when it exceeds a preset threshold. Since I'd like a little advanced warning, I think 70% would be a good value.