I didn't plan on doing temperature profiling when I initially modified my HX to be flush-free Creating the fully programmable HX espresso machine?, but I've since wondered how well it would adapt to this. So I made my pseudo-Scace last night (thermocouple over an ESE pod) and took these measurements today.

The two traces were taken from the same machine about 6 minutes apart (and both were done with no flushing). I don't know if a 1-degreeF initial hump is significant (I wasn't about to taste what came thru the pod on the third or fourth use), but it shows that crude temperature profiling can be done by mere humans.
I did learn something new about my Expobar Office... when pulling a shot it now sends water thru the thermosiphon return as well as the feed path. My tests that I did on the unit when it was new suggested that the siphon return was blocked off during pulls. So to get the shots that are plotted above I had to close the siphon return during the pulls. Without doing this, the temperature rises 2 or 3 degrees during the pull, even though the EricS sensor says the temp is dropping slightly. I don't know if my 3-way solenoid valve is getting leaky, or if my initial testing was flawed.
-Ed