Reefkeeper Temperature Calibration?

[Codeman00]

I finally hooked up my Reefkeeper for the first time and it looks like the temperature is on the low side and needs to be calibrated. My digital house thermostat reads 74 F and the reefkeeper with new, unheated water shows 68.7 F. I have a digital multimeter to verify temperature, but it only has a +/-3%+3 degree accuracy (which doesn't sound accurate at all?).

I'm surprised that it doesn't come close to being accurate out of the box. 5 degrees off is alot! Did you guys have to calibrate your Reefkeeper temperature? If you did, what did you use to get an accurate measurement to set it to? Any suggestions?

[Codeman00]

Entropy...I just read your tip in another post about icewater...32F. That's a great reference point..and I'm not sure why I didn't think of it. Thanks.

[Codeman00]

Great...the ReefKeeper temp probe doesn't like temps under 50F. It says "Probe Removed" on the screen. I guess the great idea didn't work afterall and I still need help calibrating this thing.

[jpfelix]

just grab all the thermometers you can fit into a water sample and take the average.

just kidding, i often worry about these issues myself and am curious as to what da says.

[Codeman00]

Originally posted by jpfelix
just grab all the thermometers you can fit into a water sample and take the average.

just kidding, i often worry about these issues myself and am curious as to what da says.

That's actually going to be my plan if I don'g get any good ideas. Ticks me off that a $200+ device that reads to the tenth of a degree is 4-5 degrees off right out of the box.

[jpfelix]

unfortunately everthing in life is relative. if only all therms. were calibrated to absolute zero!

[CCG]

What I would do is to get your most accurate thermometer and calibrate it in an ice bath that way you will know its right. Stick that thermometer in your tank and then calibrate the RK to that thermometer.

Colin

[Codeman00]

CCG...good idea. This afternoon I went to Petco and Petsmart to look for a reliable thermometer. Actually, some of the thermometers were so inexpensive that I bought 3. I bought a thermal strip, a mercury filled glass float type, and a Lifeguard Little Time or Temp Digital Clock/ Thermometer. BTW, The same Lifeguard digital is only $18 at Petsmart and $30 at Petco!

When I placed all 3 of the thermometers in the sump next to the Reefkeeper thermocouple...I found out that the original Reefkeeper temperature wasn't that far off after all (before I adjusted it to my multimeter reading). Although its hard to get a good resolution on the thermal strip or mercury....all 3 were very consistent with one another from what I could read.

I then dunked the Lifeguard digital in icewater and let it reach steady state and it showed 32.2F. Not bad. I have now adjusted to the Reefkeeper thermostat up 0.2 deg F to compensate. All is good now and I'm glad my tank is now reading 78.5F without lights on instead of 84F.

Thanks for your help guys and my apologies to the guys at Digital Aquatics about the temp being off. It was pretty much accurate out of the box. One suggestion for them to have the Reefkeeper able to be calibrated in an ice bath instead of flashing a Probe Removed warning. And also, have this method of calibration described in the manual. That would help out a lot I think.

[Leishman]

I agree on the ice bath method. My unit came in today and the 1st thing I did was an ice bath only to see "Temp Probe Removed". Kinda frustrating to go have to go out and spend good $ on a "Good" thermometer, especially after just dropping over $300 on the RK2 which I thought would be calibratable (is that even a word) @ freezing or boiling pionts.

This would be an awesome upgrade for new software, even if we need to shellout for a new probe.

-Rik