Apex Users: how and how often do you calibrate your temp probe?

[ZoWhat]

Apex Users: how and how often do you calibrate your temp probe?

I try to calibrate mine twice a year. it's amazing to find it can be as much as 2degrees off if you don't recalibrate it every so often.

I know algae build up effects the probe TREMENDOUSLY

(pic below) Heres how I recalibrate it using a bowl, hot tap water and a oral thermometer that ranges from 90degrees to 104.

I think its important that the Alex probe stays SUSPENDED in the sample water without the tip of the probe touching the bowl. hence the reef toothbrush in the pic to LIFT to probe up.

I take sample test temps prob 50+ times over 39mins until I'm satisfied the two #s are CONSISTENTLY within +/- 0.2 degrees

 

[christopher.lauwers]

I never have don’t my temp probe. I have a digital one that I keep next to it and compare the 2.

But I’d second the post about the ph probe. Sorry to hyjack.

 

[Brett S]

(pic below) Heres how I recalibrate it using a bowl, hot tap water and a oral thermometer that ranges from 90degrees to 104.

The problem with this is that your calibration is only as good as the standard you use to calibrate it. And frankly I would probably trust that cheap CVS thermometer less that I would trust an uncalibrated apex temp probe. I suspect if you got two of three of those CVS thermometers they would all read different temps.

The other issue is that you really should calibrate at as close to the temperature range that you plan to test as possible. Even if your apex thermometer is off by 20% if you keep your tank at 78 degrees and calibrate at 78 degrees then your inaccurate thermometer will still be accurate at the 78 degrees it was calibrated at. The farther you move from the value you calibrated it at the more any potential errors or inaccuracies can affect your reading. Calibrating at 90+ degrees isn’t really ideal since we keep our tanks at a much lower temp.

 

[ZoWhat]

what start this whole thing for me is my Apex temp probe has been reading 82-83 degrees....I put my hand in the DT I said, "no way does that feel like 83○ water"

I live around a TON of lakes and boat a LOT. btwn swimming and skiing in lakes I know generally what 80+○ water feel like.

IME the two main factors that effect an Apex temp probe is:

> algae or film that needs to be cleaned off the probe..I've seen a good probe cleaning lower the temp reading by 2○

> age of the probe..just like ph probes I'm sure my 8yr old Aoex probe is out of calibration due to age. Apex wouldnt have put the ability to adjust temp calibration if they felt their probes were lab grade for 5+ years

I do AGREE with testing and calibrating as close to 80○ as possible due to "slopes" causing errors.

if only kept my mom's 1970s mercury thermometer. urgh!

most $10-$20.lab grade thermometers on Amazon still only test out at +/- 1.0 degrees.

I'm sure my CVS oral thermometer is accurate with the 90-110 range +/- 0.5 degrees.

Any other thoughts of what instrument to use to deliver a 75-80○ sample?

 

[Brett S]

Well, depends on how much you want to spend, but this one is calibrated to the NIST standard.

Thermco ACC611SSCFC NIST Traceable Factory Certified Glass Spirit Filled Thermometer, Total Immersion, -20 to 110 Degrees C, 1.0 Degrees C Division, 305 mm Length https://www.amazon.com/dp/B01N1X1K2Y/ref=cm_sw_r_cp_tai_GtrcDbDKFKXY7

 

[ZoWhat]

Well, depends on how much you want to spend, but this one is calibrated to the NIST standard.

Thermco ACC611SSCFC NIST Traceable Factory Certified Glass Spirit Filled Thermometer, Total Immersion, -20 to 110 Degrees C, 1.0 Degrees C Division, 305 mm Length https://www.amazon.com/dp/B01N1X1K2Y/ref=cm_sw_r_cp_tai_GtrcDbDKFKXY7

getting Apex temp probe roughly around +/- 1○ is important to me

but at $193 to get it within +/- 0.5 ○ .... forget it. lol

I'd totally buy a mercury thermometer off the dark web if it weren't for me being put on some NSA Watch List for being in the dark.web....