Can’t seem to get my salinity probe calibrated properly. Left it out to dry all night. Can’t get past first part of auto cal. Did manual cal. And it’s closer but still reading 42 when I know it’s 35. I have tc factor set at 2.2. Getting frustrated. It’s new btw.
Apex salinity probe calibration
- Thread starter Kzguns
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mckinney0171
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make sure you are shaking it real good inside the calibration solution bag to get any bubbles out. that was the issue that i had. once you get these things calibrated they are pretty bulletproof. i honestly have never had to re-calibrate mine even though i probably should. i also keep mine in the water sideways and away from the flow of current in my sump to keep bubbles from getting trapped underneath. not sure if that helps or not but that's what i do.
SPR1968
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I had the same problem especially when using the solution.
So when I calibrate I do it when my Refractometer (which I trust because everything is alive!)reads 35 and then when the calibration calls for the probe to go in the solution, it goes back into the tank water instead. And it’s generally been fine doing this.
So when I calibrate I do it when my Refractometer (which I trust because everything is alive!)reads 35 and then when the calibration calls for the probe to go in the solution, it goes back into the tank water instead. And it’s generally been fine doing this.
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Randy Holmes-Farley
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That means the calibration solution is reading 42 ppt when it is a 35 ppt calibration solution, or are you talking about tank water reading 42 ppt after calibration?
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User1
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Similar issue here. Upon first calibration I used the shipped solution and it was off. Read a bit on Neptunes forums and found a thread about how to properly or at least consistently, calibrate the probe. One piece of information that I missed was to put the calibration packet / fluid into the tank or sump to bring it up to the same temperature. Then like others mentioned move it around inside the solution to remove any bubbles. Once I did this it was reading more or less the same has my digital tester.
So for me the main key was to bring it to the same temperature has the tank then calibrate.
So for me the main key was to bring it to the same temperature has the tank then calibrate.
Artillerydrill
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Get some canned air to dry it out that should get you to zero at least. Then throw it in the tank for your 35 reading. As long as you know what the numbers are you will know if you are getting swings and the ato fails etc.
Randy Holmes-Farley
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Why do you need to dry it out? That's not a necessary part of calibrating a normal conductivity meter. :)
Artillerydrill
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Just something i pulled off of the apex forums after hours of frustration myself.
Randy Holmes-Farley
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Doesn't it read zero before being "dried"?
Maybe it's some unusual design that doesn't drain itself well, but all the conductivity meters I've ever used (many over the years, hobby to high end) drop immediately to zero conductivity immediately on being withdrawn from the solution.
Presumably they are worried about conductivity through the residual water stuck to the sides of the device.
In any case, there is typically no "setting" of the zero point. Zero is zero.
Maybe it's some unusual design that doesn't drain itself well, but all the conductivity meters I've ever used (many over the years, hobby to high end) drop immediately to zero conductivity immediately on being withdrawn from the solution.
Presumably they are worried about conductivity through the residual water stuck to the sides of the device.
In any case, there is typically no "setting" of the zero point. Zero is zero.
Randy Holmes-Farley
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FWIW, it is really shocking to me how many people have issues with controllers and conductivity. I have to believe they just have a problematic implementation somehow, since such issues do not seem to arise nearly as often in using stand alone conductivity meters.
I even just watched a long video by them discussing the "issues". Why are there so many issues? lol
I even just watched a long video by them discussing the "issues". Why are there so many issues? lol
As I understand it is the residual water issue allowing some conductivity. People have reported that it won’t calibrate unless actively dried during the step in calibration that calls for taking it out of solution. There are more complaints and frustration with the Apex conductivity probe than all the others combined as far as I’ve seen.
Randy Holmes-Farley
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When you pull it out of the tank, it doesn't drop to zero?
Here's a typical "problem" thread, and page 3 has several videos, including one by APEX discussing issues.
https://www.reef2reef.com/threads/contradicting-salinity-results.376757/
Here's a typical "problem" thread, and page 3 has several videos, including one by APEX discussing issues.
https://www.reef2reef.com/threads/contradicting-salinity-results.376757/
Artillerydrill
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Mine doesn’t drop to zero and when it can’t hit zero it can’t be properly calibrated. Of course you can use simple math to figure the deviation in the numbers but what’s the point if you’ve spent all the money
Randy Holmes-Farley
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Then it must either be a bad probe design, or bad software. :(
I just tried my Orion model 128 conductivity meter with a 4 electrode probe. I dropped it in a salt solution that was about 25 mS/cm. It gives a new reading about once a second, and with one update after being pulled from the solution, it read 0.0 mS/cm. I switched it to a lower conductivity scale, and it read about 50 uS/cm. So the drop within a few seconds is a factor of 500 in terms of conductivity (and that's a salty water solution on it, not residual RO/DI).
You'd think if they used a good probe and good software, you would not need to dry it.
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