APEX salinity probe keeps climbing - do I need to re-calibrate?

[BanjoBandito]

Check out this thread. This worked wonders for my salinity probe stability.

(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor

I was trying to calibrate my new salinity probe a few weeks ago, and ran into all sorts of problems. Calibrations that were way off the mark, big fluctuations in readings that couldn't possibly be correct (and were verifiably not), etc. After searching around the internet, it was clear that a...

www.reef2reef.com

Sean, did you recalibrate then set the TC factor? Is that what I'm reading?

 

[Sean Clark]

Sean, did you recalibrate then set the TC factor? Is that what I'm reading?

I adjusted the TC and then recalibrated ensuring the temp of the solution was the same as the tank. It is also important that the temp probe and salinity probe are both plugged into the same module for some reason that I cannot recall. My TC factor is now set to 2.2, it was 2.8 before I mad the adjustment.
This shows my results before and after the change.

(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor

I was trying to calibrate my new salinity probe a few weeks ago, and ran into all sorts of problems. Calibrations that were way off the mark, big fluctuations in readings that couldn't possibly be correct (and were verifiably not), etc. After searching around the internet, it was clear that a...

www.reef2reef.com

 

[BanjoBandito]

I adjusted the TC and then recalibrated ensuring the temp of the solution was the same as the tank. It is also important that the temp probe and salinity probe are both plugged into the same module for some reason that I cannot recall. My TC factor is now set to 2.2, it was 2.8 before I mad the adjustment.
This shows my results before and after the change.

(Almost) Everything You Need to Know About Apex Salinity Calibration and TC Factor

I was trying to calibrate my new salinity probe a few weeks ago, and ran into all sorts of problems. Calibrations that were way off the mark, big fluctuations in readings that couldn't possibly be correct (and were verifiably not), etc. After searching around the internet, it was clear that a...

www.reef2reef.com

OK so I'll set the TC then recalibrate and hopefully that gets me settled.

 

[BanjoBandito]

OK, I'm about to do this recalibration....so I am reading that I should SET THE TC first, THEN recalibrate? Will keep this thread posted on results.

 

[Sean Clark]

OK, I'm about to do this recalibration....so I am reading that I should SET THE TC first, THEN recalibrate? Will keep this thread posted on results.

That is how I did it. The way I understand it the TC is only adjusting the curve, not the 53000us set point of the calibration. So in theory, it should not matter.

 

[Randy Holmes-Farley Verified Community Expert]

If the standard is not at 25 deg C, you need to make sure it is properly temp corrected by checking the temp correction stuff first.

 

[BanjoBandito]

If the standard is not at 25 deg C, you need to make sure it is properly temp corrected by checking the temp correction stuff first.

I think I did all that, I'm getting a 36.8 ppt reading from the probe and my refractometer is showing 1.026 with a ambient temp of 77.3 ish....so....CLOSE ENOUGH? I think that's pretty close with the new fiddling. I'm going to monitor it for stability. Stability has been the whole mechanism for this action. My probe was "jumping" in weird ways, specifically very high for no real reason. So HOPEFULLY this will settle it down a bit.