The first image shows my Bunn ES-1A's temp at the puck using the thermocouple-over-the-lip technique. In this image I've restricted the group flow to 2 ounces every 30 seconds.
I ran the test for as long as the digital thermometer could record - 99 seconds. A bit extreme, but I wanted to make sure the intra-shot temp didn't deviate too much when I regulated the outflow. I limited the flush cycle to 4 ounces, which may explain the initial temp spike? The flat-line beginning temp represents the effects of pre-infusion warming the puck.
That's more or less what I expected to see. Now I just need to recheck the thermocouple/thermometer accuracy, and maybe lower the boiler temp.
The second image shows the group temp stability at idle. Rock solid!
This is what good HX machines are known for - rock solid temp stability. I don't want to show the results for the Silvia and Gaggia machines I've tested; it's too unfair to compare apples & oranges!
