Year another Apex Salinity Probe issue

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sandfan85

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Another salinity probe issue. Replaced my old probe with a new one and I’m having issues with it reading correctly. I’m hoping somebody will be able to point in a direction I haven’t already been. Here’s what I’ve done so far.

*New probe
* waited a week to calibrate (break-in procedure???)
*calibrated with 53,000 micro Siemens
*tried manual and automatic calibration.
*disabled probe, disconnected probe, reconnected probe and re enabled probe
* checked for bubbles.

Here’s the issue, when it’s in the tank it reads 31.8 when I pull it from the tank and stick it back in the calibration solution, it reads 34.9 I’ve re routed the wire to ensure it’s not getting any “cross talk” from another wire. Any additional advice would be greatly appreciated.
 
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Zzyzx

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Another salinity probe issue. Replaced my old probe with a new one and I’m having issues with it reading correctly. I’m hoping somebody will be able to point in a direction I haven’t already been. Here’s what I’ve done so far.

*New probe
* waited a week to calibrate (break-in procedure???)
*calibrated with 53,000 micro Siemens
*tried manual and automatic calibration.
*disabled probe, disconnected probe, reconnected probe and re enabled probe
* checked for bubbles.

Here’s the issue, when it’s in the tank it reads 31.8 when I pull it from the tank and stick it back in the calibration solution, it reads 34.9 I’ve re routed the wire to ensure it’s not getting any “cross talk” from another wire. Any additional advice would be greatly appreciated.
There’s a very nice article or thread on here which goes into great detail on how to program and calibrate the salinity probe. I can’t see so it’s hard for me to copy and paste. Hopefully someone can link it or you can search to find it. It goes over all the common issues with calibrating someone put a lot of time and effort into it, just wish I could link it for you

edit. it’s titled almost everything you need to know about the apex salinity probe, or something close to that
 
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sandfan85

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There’s a very nice article or thread on here which goes into great detail on how to program and calibrate the salinity probe. I can’t see so it’s hard for me to copy and paste. Hopefully someone can link it or you can search to find it. It goes over all the common issues with calibrating someone put a lot of time and effort into it, just wish I could link it for you
Thank you, I’ve already read that article as well. None of which has helped in my case
 

Zzyzx

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Thank you, I’ve already read that article as well. None of which has helped in my case
Ok. I’ll tell you what I do but everyone will tell you not to do it. Quadruple check that your tank salinity is on point. Calibrate the dry as normal then use the tank to calibrate the 53000. Bam, done. Salinity will read 35 plus or minus and it works to monitor trends.

edit. I’ve been doing that for many years as I’m ocd and can’t stand having the number off.
 
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sandfan85

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That was my next plan. I’ve got a manual refract and a Milwaukee refract. I’m going to test with both and then use the tank as calibration solution. I even thought maybe I had some stray voltage that was causing the difference in readings. But I double checked with multimeter and no voltage found. Stumped :\
 

Zzyzx

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That was my next plan. I’ve got a manual refract and a Milwaukee refract. I’m going to test with both and then use the tank as calibration solution. I even thought maybe I had some stray voltage that was causing the difference in readings. But I double checked with multimeter and no voltage found. Stumped :\
Usually it’s the temp compensation, calibration solution not the same temp as the tank water, the sensor not being dry, or a combination of. Plus it’s reading conductivity and converting that to salinity. Easiest is to cal to tank if you must have it read 35.0 like me being ocd. Otherwise just let it read 32ish and know that’s your number. It’s really only for monitoring trends anyway. We all should be verifying salinity every now and then anyway. I check the tank every time I mix salt, I have the tool in my hand anyway
 

Lbrdsoxfan

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Ok. I’ll tell you what I do but everyone will tell you not to do it. Quadruple check that your tank salinity is on point. Calibrate the dry as normal then use the tank to calibrate the 53000. Bam, done. Salinity will read 35 plus or minus and it works to monitor trends.

edit. I’ve been doing that for many years as I’m ocd and can’t stand having the number off.
This. Its the only way I can even get close.
 

All_talk

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I believe I read that you need to put the temp probe in the solution with the salinity probe to get it to calibrate correctly, i.e. at the same temp. And also that the temp probe needs to be connected to the same module as the salinity probe, i.e. both connected to the base unit or both connected to the PM2, not mixed.
 
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sandfan85

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That’s actually a great idea. I never thought of having the temp probe and salinity probe in the same calibration solution. This way you ensure both are at same temp
 
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