Frank, I was scoping out the Auber unit for the same purpose on my compact. The manual indicates a very low power draw so my plan was to tap into the power supply using the leads for the power light on the front lower panel and run the wire directly out the bottom of the frame to where the PID would sit. Eric's post has made me rethink this... having its own power supply makes it easy to temporarily move to other machines. I was planning to drill/tap the 20mm cap on the top of the group for the probe for this RDT sensor (the auber PID will read a RTD or a TC.

http://www.auberins.com/index.php?main_page=product_info&cPath=15&products_id=136

Which probe were you planning to use?

Always buy spare cap(s) for your machining adventures, regardless of your skill level. They are readily available and relatively inexpensive.

I'm also tapping the m20 cap. However, I was planning on using a swagelok adapter with a 1/16" thermocouple from omega. Someone with more knowledge of temperature probes than me can confirm this, but I think that RTDs are more accurate but have a slower response time than thermocouples.

I use the Sweet Marias Meter for exactly this purpose and though it works well I've been thinking of going to the auber pid since it can be hard wired

The sm meter burns through batteries -about one 9 volt a month - and it's accuracy is is based on battery level. Also the real source for that meter is here: http://www.web-tronics.com/

Simply as an FYI, the meter which Sweet Maria's sells is pretty nice. It reads C or F and has a hold function. C reads to the tenths up to 150C and F reads tenths till 200 F. I ordered and received two and based on a test of one, it read 0.75 F low (not a big deal). It comes with one Type K thermocouple (nice construction) and zippered case.

I finally got around to installing the thermocouple in my group head. I drilled and tapped the cap on top of the expansion chamber. Then I screwed a Swagelok compression fitting into that. The compression fitting holds a thermocouple in the chamber. For the thermocouple, I chose the Omega 1/16" hollow-tube thermocouple. For the meter, I decided on the Auber PID, which I wired directly into the main power of the machine. It works perfectly and has yielded some interesting information so far. Thanks to erics for the invaluable information on HB and on his website.

Here are some pics: