I personally postponed the purchase, so I have not yet hands on experience.

But I happen to be about to (tomorrow, actually!) buy an AKCP Sensor Probe 8 (http://www.akcp.com/products/sensorprobe-series/sensorprobe8/) .

In fact, I found out that a friend I trust, working in another organization, is using them since years ago, and they seem to just work.