APEX Jr. Temperature probe accuracy

ENARP · Mar 17, 2016

Just starting a new tank and trying to get everything dialed in. My Apex Jr. Temp reads 77.2, my floating thermometer reads 75, my digital hand held probe read 79.3. I know it ain't 79 degree,s so let's ax that one. I am leaning towards believing the Apex more than any of the others, but want to learn from anyone out there who has more experience with APEX probes and can give me any more info. on their accuracy. Can someone recommend an accurate floating thermometer? My LFS had only stick on strip thermometers and one that I had already read bad reviews on.

jaws789832 · Mar 17, 2016

The probes are hit or miss. The first one that came with my apex was real accurate (still is) The I bought another one for the Salinity module and it was 2 degrees higher. I went out and bought a NIST thermometer (you can get them online fairly cheap) and had to calibrate the second probe down 2 degrees. That's about the only way that I know of you can check for true accuracy

hybridazn · Mar 17, 2016

Neptune suggests calibrating the temp probe to a nist thermometer

ENARP · Mar 18, 2016

Just ordered NIST thermometer! Thanks

blacktippr · Mar 18, 2016

jaws789832 said:
The probes are hit or miss. The first one that came with my apex was real accurate (still is) The I bought another one for the Salinity module and it was 2 degrees higher. I went out and bought a NIST thermometer (you can get them online fairly cheap) and had to calibrate the second probe down 2 degrees. That's about the only way that I know of you can check for true accuracy

I had the same issue, I have 2 temp probes one inside the tank and the one hooked up to my salinity probe was 2 degrees higher, calibrated with a Hanna NIST traceable and now my salinity probe reads dead on. I had been fighting the issue that my salinity probe read a full 1 ppt below what it really is.

So do calibrate with a NIST TRACEABLE thermometer.

David Cher · Mar 27, 2016

ENARP said:
Just ordered NIST thermometer! Thanks

Any brand ???

blacktippr · Mar 27, 2016

Hanna Works Nice , got it On Amazon . Its uses in food preparation by chefs. It's NIST traceable. To +_1 degree.

David Cher · Mar 27, 2016

blacktippr said:
Hanna Works Nice , got it On Amazon . Its uses in food preparation by chefs. It's NIST traceable. To +_1 degree.

which one did you purchase ? any model number?

Sabellafella · Mar 27, 2016

When you add a temp probe to the pm2 its wayy off, you have to calibrate the probe on the pm2 mod. The temp that comes with apex straight into the brain is fully calibrated unless you got a dud.

ENARP · Mar 27, 2016

I ordered from Thomas Scientific ..Easy-Read® Precision Thermometer, 20/230°F x 2°F, 200mm, Total Immersion (9313A80)

blacktippr · Mar 27, 2016

David Cher said:
which one did you purchase ? any model number?

ckozma · Mar 28, 2016

Sabellafella said:
When you add a temp probe to the pm2 its wayy off, you have to calibrate the probe on the pm2 mod. The temp that comes with apex straight into the brain is fully calibrated unless you got a dud.

I know how to calibrate the first temp probe that is linked straight into the apex, and I know how to calibrate the salinity probe that comes with the PM2 because the instructions for the apex gold state how to do this. But nowhere does it state how to calibrate the second pm2 temp probe? My temp probe plugged into the pm2 reads 1.5 degrees higher than the one linked straight into the apex at all times. The pm2 temp reading is too high.