Calibrating Temperature Controller: What to use?

[ariellemermaid]

What does everyone out there use to calibrate your temperature controller? This all started because I noticed my Hanna salinity checker is consistently 1 degree below what my controllers say. Here are my options:

1. The controller itself.
2. Cheap glass thermometer that came with a 20g tank: 72 degrees. So that’s useless.
3. Infrared thermometer from a local hardware store: agrees with the temperature controller.
4. Hanna salinity checker: consistently 1 degree below the controller.
5. Seneye: 1.2 degrees below the controller.

I’ve never considered the infrared to be a gold standard on temperature but it’s interesting it agrees with the controller. I hope the Hanna salinity is accurate otherwise my PPT is off. Also interesting the Seneye agrees with Hanna.

So, where would you set the controller in this case? I’m not going to buy some crazy expensive instrument over a possible 1 degree variance.

 

[reefwiser]

Infrared is not good to calibrate. The best is a temperature metal probe.

 

[ariellemermaid]

Infrared is not good to calibrate. The best is a temperature metal probe.

So the Hanna salinity checker? Definitely a metal probe. The fact that it doesn’t have a temp calibration option tells me they’re pretty confident in it. Or just didn’t want to include extra buttons.