Neptune Apex Conductivity Probe - I understand it now

[ZoWhat]

This is more or less just a documentation of some knowledge I discovered.... after 3 weeks of struggling to get my calibrated probe to read and be stable at 34~35 SG (meaning my actual SG was 35 but my conductivity kept reading 29.x no matter how many times I recalibrated)

Given this frustration, I did a lot of reading on Neptune's site and read that this probe measures the conductivity of the water in relation to the the amount of salinity (salt) in the water. A measurement called sM/cm

There are three measuring #s to measure the amount of salt in one's tank
* SG
* Salinity
* Conductivity

This CONDUCTIVITY probe is reeeeeeally not a true direct monitor of SG nor Salinity... in the direct sense. It's attempting to indicate what SG is thru conductivity measuring.

Write ups went on to say it very hard to match conductivity (that this probe measures) to match exactly SG in the water in terms of both #s being the same #

Meaning.... that when SG is 35 the probe indicates a "35" in conductivity. SG is 30 the probe reads "30" in conductivity.

Veeeeery difficult for the two #s to be in direct exact parallel with each other bc this probe is effected by many factor including temp, micro air bubbles in the water and other equipment sharing the water with just the slightest of stray voltage.

It's not a SG monitor probe.
It's measures conductivity, period, end of story.

It's a conductivity probe to set up alarms that if the the conductivity # goes higher, SG is going higher and time to add RODI to bring it back down in-range.

I'm renaming my probe as "sM/cm" as it's Apex name and whatever conductivity it's measuring.... thats the # I'm living with.

I will watch that # as it rises or fall as a indirect indicator as to what's going on with my SG/salinity

Gone is my thought process of seeing a conductivity # of 30.x and saying "geez it's 5 points lower than its true 35.x SG #"
.

 

[melonheadorion]

soon after i got my apex, i found out that just about every number that the apex provides, has issues, except maybe temp.
through the reading, if i recall correctly, pH reading is something similar to how salinity is read. i have come to just accept that the numbers are not right, and use it to monitor swings, and just massive changes that might tip me off to issues.
another thing to note; since these probes basically measure conductivity, they are succeptable to electical interference that can causes the numbers to be wrong, fluctuate, etc. so when youre running the wires for the probes, you want to have them away from electrical cords, or anything else that may have electrical interference. you may have seen suggestions on this, when you read up on their forums

 

[Gadbery]

This is more or less just a documentation of some knowledge I discovered.... after 3 weeks of struggling to get my calibrated probe to read and be stable at 34~35 SG (meaning my actual SG was 35 but my conductivity kept reading 29.x no matter how many times I recalibrated)

Given this frustration, I did a lot of reading on Neptune's site and read that this probe measures the conductivity of the water in relation to the the amount of salinity (salt) in the water. A measurement called sM/cm

There are three measuring #s to measure the amount of salt in one's tank
* SG
* Salinity
* Conductivity

This CONDUCTIVITY probe is reeeeeeally not a true direct monitor of SG nor Salinity... in the direct sense. It's attempting to indicate what SG is thru conductivity measuring.

Write ups went on to say it very hard to match conductivity (that this probe measures) to match exactly SG in the water in terms of both #s being the same #

Meaning.... that when SG is 35 the probe indicates a "35" in conductivity. SG is 30 the probe reads "30" in conductivity.

Veeeeery difficult for the two #s to be in direct exact parallel with each other bc this probe is effected by many factor including temp, micro air bubbles in the water and other equipment sharing the water with just the slightest of stray voltage.

It's not a SG monitor probe.
It's measures conductivity, period, end of story.

It's a conductivity probe to set up alarms that if the the conductivity # goes higher, SG is going higher and time to add RODI to bring it back down in-range.

I'm renaming my probe as "sM/cm" as it's Apex name and whatever conductivity it's measuring.... thats the # I'm living with.

I will watch that # as it rises or fall as a indirect indicator as to what's going on with my SG/salinity

Gone is my thought process of seeing a conductivity # of 30.x and saying "geez it's 5 points lower than its true 35.x SG #"
.

Isn’t that BS though. The dang APEX Home Screen shows salinity reading and says PPT under it. Been messing with mine the last week and I think your right it’s a conductivity reading not a PPT