neptune salinity probe

[Milangupta]

Hi,
Does anyone have the tech specs/info for the neptune salinity probe ?
Specifically -
1. Is it an ion selective probe (ISE) or a conductivity probe ?
2. If an ISE, what exactly is it measuring ? Just sodium ions or all salts (Na, Mg, Ca, ...) ?
3. What is the K factor for the probe ? Is it K=0.1 or K=1.0 or even K=0.5 ?

I have figured out the pinouts already, and from experiments using off the shelf K=1.0 conductivity probes, I am getting a 2x reading for salinity (Some salinity monitors use conductivity as an extrapolation for salinity).

My next step is to try calibrating, however, I suspect the software will limit this (out-of-range reading) and if the probe's range is wrong, it will not be compatible without a 2 point calibration for salinity/conductivity (which neptune software doesn't support).

Thanks in advance ..

 

[scuba steve]

The Neptune salinity probe is a conductivity probe.
Calibrating it requires holding it out of water for one point, and then immersing in calibration solution for the second.

 

[enderg60]

This thread could help.

Salinity Probes that work with the Apex

Does anyone know if there is a cheaper solution for the salinity probes? The only ones I have seen have been in the $120 range and the Neptune salinity probe has bad reviews. Any info on cheaper or even just better probes for the price is much appreciated. Thanks.

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