Not perfect temp compensation in my apex

[JonasRoman]

Hi

Just purchased salinity probe to apex.
Through the pm2

I use temp comp but it seems to overcompensate. With temp compensation there should be a reasonable straight line but it still follows the temperature BUT in opposite direction than within compensation thus an overcompensation. I guess?

So I settled the factor to the lowest recommendation 2.0% but still the “salinity “ graph is inverted the temp.

You with this feature and temp compensation. Have you managed it to temp compensate properly? What factor do you use? Maybe I shall lower to 1.9%??
But that is lower than “science “ that says it’s around 2.0-2.1 when a solution is NaCl dominated.
I have talked to support and they been very quick and good, and advise me to recalibrate , I will do that. But this shouldn’t just change the baseline but not change the temp behaviour..??

If I use temp comp I would like to see a reasonable straight graph. Isn’t that true?

Thanks for input

Jonas Roman

 

[Brew12]

I often wondered about this also. When I researched it, I found that ocean water at reasonable temperatures could have a correction factor of anywhere from 1.8 to 2.2 depending on the specific chemical composition.

I will be honest, I never completed this research because I realized that my salinity probe would only stay accurate for a few days after calibration and so I felt it was not worth the effort.

 

[JonasRoman]

So same experience though. Now when I have got answers from more users it seems like all of them so far have same graph appearance so maybe the cal factor actually should be 1.8-1.9 and not 2.1-2.3 as it says in manual.
I will simply try to lower until I got a straight line.

Jonas

 

[mitch91175]

So same experience though. Now when I have got answers from more users it seems like all of them so far have same graph appearance so maybe the cal factor actually should be 1.8-1.9 and not 2.1-2.3 as it says in manual.
I will simply try to lower until I got a straight line.

Jonas

Curious how this goes @JonasRoman. I have just given up on trying to get it to a straight line and just use it as a gauge these days. Still rely on my refractometer when I feel the need to get an accurate measurement.

 

[ca1ore]

Same here. I just use the conductivity probe as an alert for changes in the baseline. I'd say it would most unwise to use it to control anything. Just the other day mine dropped from its nominal 35 to 32.5 ...... then a day later it was back to 35. What happened ...... nothing as far as I could tell. Any kind of automated intervention would have been counterproductive; but the alert was useful to check to make sure the ATO hadn't stuck open.