let me kid no one not.... this is one big chunk of copper....
had it on a 12v car battery here, running the two elements in parallel.... took it about 5 minutes to get up to 55ºC... then I dis-connected, it's now 15 minutes after that, and it's slowly starting to come down.... about 0.1ºC every 10 seconds....
this thing should be awesome for getting some real accurate and extremely stable measurements.....