Do new Apex COND probes need to break in

[Jyetman]

Just installed a new salinity probe. First calibration with temp probe to PM2 in same solution 5300 was high so recalibrated next day and now readings are low? Do these probes need to break in first the results are all over the place?

[slief]

It's been said that the probes do require some break in period before they will become accurate. I would allow the probe to sit in the tank water for several days before re-calibrating it.

I've been running my probe for years now and don't recall the initial accuracy when I first set it up but I do find it to be very consistent and reasonably accurate. As I and others mentioned in your other threads, these probes are not ideally suited to be your sole source of salinity measurement. Instead they are best suited to be used for trends. In my case, I use it as part of my failsafes for my ATO and my auto water changer. That said, if I compare the Apex conductivity to the salinity reported by my refractometer, they are generally within .001 SG of each other which is well within the accuracy that I would expect from either the probe or the refractometer. I will also note that I have two bottles of Pin Point 53000 mS solution and both result in slightly different readings with my refractometer. While the difference isn't huge at about .001, it's enough to make me scratch my head. On the very rare occasion that I calibrate my Apex CondX probe, I always use the Neptune calibration solution as I trust their solution better than the stuff I calibrate my refractometer with.

With your initial calibration, I think you indicated that your probe was reading .0005 difference between your presumed salinity which is very reasonable.

[Jyetman]

Originally Posted by slief

It's been said that the probes do require some break in period before they will become accurate. I would allow the probe to sit in the tank water for several days before re-calibrating it.

I've been running my probe for years now and don't recall the initial accuracy when I first set it up but I do find it to be very consistent and reasonably accurate. As I and others mentioned in your other threads, these probes are not ideally suited to be your sole source of salinity measurement. Instead they are best suited to be used for trends. In my case, I use it as part of my failsafes for my ATO and my auto water changer. That said, if I compare the Apex conductivity to the salinity reported by my refractometer, they are generally within .001 SG of each other which is well within the accuracy that I would expect from either the probe or the refractometer. I will also note that I have two bottles of Pin Point 53000 mS solution and both result in slightly different readings with my refractometer. While the difference isn't huge at about .001, it's enough to make me scratch my head. On the very rare occasion that I calibrate my Apex CondX probe, I always use the Neptune calibration solution as I trust their solution better than the stuff I calibrate my refractometer with.

With your initial calibration, I think you indicated that your probe was reading .0005 difference between your presumed salinity which is very reasonable.

I just have to make the trends stick in my head and not focus on equal numbers. Thanks again.

[slief]

Originally Posted by Jyetman

I just have to make the trends stick in my head and not focus on equal numbers. Thanks again.

Exactly!! Sadly the most accurate measurement for testing our salinity is a refractometer but they are only as good as their quality and the solution you use to calibrate with. As I mentioned, I have seen deviations in the same solutions from the same manufacturers from one bottle to the next. As such, you just have to come to accept that you are in the ballpark and at that point, consistency is all that really matters.

[CuzzA]

Slief hit the nail on the head. After some difficulty getting mine to read 35, even though I know with 100% certainty that my tank is 35, I accepted the fact that it reads 30. I use it for trends and know it's accurate. For example, if I pull a lot of water for frags and that water is replaced with rodi water my probe will drop to 29.9-29.8 depending on how much water I pulled. This correlates with my refractometer. So ultimately I use it for fail safes.

Eventually when I have some free time I'll get back to trying to calibrate it again. Temperature is key and that's likely where I had trouble. Probably didn't wait long enough. Patience.

[Jyetman]

Can you tell me what the programming examples could be for a ATO shut off range and Warnings? Who sells the apex calibration fluid?

[slief]

Originally Posted by Jyetman

Can you tell me what the programming examples could be for a ATO shut off range and Warnings? Who sells the apex calibration fluid?

Here is my ATO code. It's kind of extensive. I use a lot of virtual outlets so much of what you see in there is virtual outlets including Salinity Low.

Fallback OFF
If Outlet AddWater = ON Then ON
Defer 003:00 Then ON
If Outlet AddWater = OFF Then OFF
If Outlet Return = OFF Then OFF
If Outlet SumpFull = ON Then OFF
If Outlet WaterBug = ON Then OFF
If Outlet SalinityLow = ON Then OFF
If Outlet SumpTooFull = ON Then OFF
If Outlet BoB_Unplug = ON Then OFF
Min Time 015:00 Then ON

Here is my Salinity Low virtual outlet programming.
Fallback OFF
Set OFF
If Condx5 < 32.0 Then ON

[Jyetman]

I just figured out what was going wrong during calibration. The cup holding the temp probe and COND probe was directly under the 160 Watt LED fixture. So the excess heat was causing improper calibrations also used a can of air to dry the probe tip one of these two things corrected the issue. Finally I'm getting near proper readings.

[Jyetman]

Originally Posted by slief

Here is my ATO code. It's kind of extensive. I use a lot of virtual outlets so much of what you see in there is virtual outlets including Salinity Low.

Fallback OFF
If Outlet AddWater = ON Then ON
Defer 003:00 Then ON
If Outlet AddWater = OFF Then OFF
If Outlet Return = OFF Then OFF
If Outlet SumpFull = ON Then OFF
If Outlet WaterBug = ON Then OFF
If Outlet SalinityLow = ON Then OFF
If Outlet SumpTooFull = ON Then OFF
If Outlet BoB_Unplug = ON Then OFF
Min Time 015:00 Then ON

Here is my Salinity Low virtual outlet programming.
Fallback OFF
Set OFF
If Condx5 < 32.0 Then ON

The virtual outlets are sure handy tool when modifying the low and high values to keep other outlets in check all made easy. Getting the hang of my Apex.

[oseymour]

those probes are affected by interference easily. try to keep the probe wire away from all other wires

[Hitch08]

Originally Posted by Jyetman

I just figured out what was going wrong during calibration. The cup holding the temp probe and COND probe was directly under the 160 Watt LED fixture. So the excess heat was causing improper calibrations also used a can of air to dry the probe tip one of these two things corrected the issue. Finally I'm getting near proper readings.

I appreciate you posting that. I'm having a tough time with mine - it's currently reading 9.0...

[FSUwxman]

A break in period for probes is normal.