Salinity Probes that work with the Apex

[kylarse]

Works perfectly, thanks.

 

[Rimsky]

Grad to hear you also had success with the Pasco probe. I think it has to be the 10X version. At least that’s the one that worked for me.

Which model did you use?

 

[kylarse]

Grad to hear you also had success with the Pasco probe. I think it has to be the 10X version. At least that’s the one that worked for me.

Which model did you use?

1x seems to work.

 

[kylarse]

1x seems to work.

 

[alabella1]

I want to share my findings with the community.

I'm just sharing my findings, but I'm not responsible for any issues that may arise. Take this information with a grain of salt, do your own research and know that anything you do is at your own risk.

Having said that...

I found a compatible conductivity (salinity) probe. It can be found on eBay. The probe has a BNC connector, but an adapter is very easy to make. The inner pin of the BNC goes to pin 1 of the mini din 4 pin connector. The outside of the BNC goes to pin 2 of the mini din 4 pin connector. That's it. It calibrated perfectly and it has been running for hours very stable.

The probe I'm using is the following: Pasco PS-2116A PasPort Conductivity Sensor P09280. The probe comes with a module that is not required at all.

Here's a picture of the mini din 4 pin female connector with the pin numbers. Imagine you are looking at the Apex head unit and this is the salinity probe female port.

My probe looks like this:

The probe itself reads: Pasco Scientific 699-06621.

That's it. Cheers!

Can you tell us more about the adapter. How did you make it? What did you use. Is it possible to just buy and adapter... like this one?

BNC to mini din

 

[kylarse]

Nevermind, 1x is limited to 200000 uS/cm, so is over range in seawater. You definitely need a cell constant of 10. Can't find the pasco 10x online, looking for an alternative.

 

[Rimsky]

Can you tell us more about the adapter. How did you make it? What did you use. Is it possible to just buy and adapter... like this one?

BNC to mini din

I’m not sure about the ready made one because I don’t know how the pins are hardwired. The pin mapping is the one I described in my post. I will share a picture of the individual parts later.

 

[Sisterlimonpot]

I have an x10 somewhere, and I remember concluding that the conductivity probe for apex is a rebranded Pasco with its own proprietary connector.

Just a word of caution, when cutting the bnc and converting it to the right connector, there needs to be really good solder joints to prevent interference and excess resistance.

The wiser choice would be to find the proper quality adapter with the proper pinout.

 

[mkoenig]

BRS has one now that is cheaper than the Neptune ones.

 

[alabella1]

BRS has one now that is cheaper than the Neptune ones.

Link? I certainly don't see it anywhere

 

[Lbrdsoxfan]

BRS has one now that is cheaper than the Neptune ones.

Thats news to me if its the salinity. Thats always been proprietary.

 

[Lbrdsoxfan]

I have an x10 somewhere, and I remember concluding that the conductivity probe for apex is a rebranded Pasco with its own proprietary connector.

Just a word of caution, when cutting the bnc and converting it to the right connector, there needs to be really good solder joints to prevent interference and excess resistance.

The wiser choice would be to find the proper quality adapter with the proper pinout.

But I believe thats how neptune made it proprietary, custom connector. I found 3 of the x10 probes from pasco, I figure for 40 bucks + the mini din connector, why not. I'm still ahead of the 180 bucks for one from Neptune.

I have a salinity probe that works fine in my case, but a spare would be nice.

+- .2 ppt in 24 hours

 

[Sisterlimonpot]

+ the mini din connector

Where did you source the s cable (mini din 4) adapter from?

 

[Lbrdsoxfan]

Where did you source the s cable (mini din 4) adapter from?

No BNC to mini din adapter, just bought some mini din ends on the web and I plan to solder them to the probe end after I snip off the BNC connector.

4 Pin DIN Male Solder Connector - Plastic

4 Pins | Solder Cups | Plastic | Molded Strain Relief | 22 AWG Wire | 7mm Cable

www.showmecables.com

 

[Sisterlimonpot]

No BNC to mini din adapter, just bought some mini din ends on the web and I plan to solder them to the probe end after I snip off the BNC connector.

4 Pin DIN Male Solder Connector - Plastic

4 Pins | Solder Cups | Plastic | Molded Strain Relief | 22 AWG Wire | 7mm Cable

www.showmecables.com

Gotcha, are you going to trial and error it? Or do you know what pins are associated with the probe?

 

[Lbrdsoxfan]

Gotcha, are you going to trial and error it? Or do you know what pins are associated with the probe?

I have a spare PM2 and a spare classic head Ill devote to the cause.

 

[Lbrdsoxfan]

@Sisterlimonpot I plan to start out my wiring odyssey with what is on post #58 in this thread. Ill also try to trace out the PM2 circuit layout to verify pins. Hopefully I'll have some answers by end of this upcoming week as everything is on order.

 

[Lbrdsoxfan]

To follow up, the pasco 10x probe works, just as @Rimsky said. As I still dont have the mini din connector (shipped but not arrived), but I hooked the wires directly to the PM2 input based on the instructions on post #58, and it works.

On a side note I do understand why the price of the salinity probe shot up via Neptune, pasco retired this particular probe a few years ago (early 'vid days) and there are only a finite number of them left in stock. I bought 3x through ebay used and the pasco probe works just as the same as neptune model does. I plan to place it in my sump next to the current one I have in service for some comparisons. That will be in the next few days after I receive the mini din connector to solder it on to the end of the pasco probe.

Quick raw you tube clip...

 

[Sisterlimonpot]

I want to share my findings with the community.

I'm just sharing my findings, but I'm not responsible for any issues that may arise. Take this information with a grain of salt, do your own research and know that anything you do is at your own risk.

Having said that...

I found a compatible conductivity (salinity) probe. It can be found on eBay. The probe has a BNC connector, but an adapter is very easy to make. The inner pin of the BNC goes to pin 1 of the mini din 4 pin connector. The outside of the BNC goes to pin 2 of the mini din 4 pin connector. That's it. It calibrated perfectly and it has been running for hours very stable.

The probe I'm using is the following: Pasco PS-2116A PasPort Conductivity Sensor P09280. The probe comes with a module that is not required at all.

Here's a picture of the mini din 4 pin female connector with the pin numbers. Imagine you are looking at the Apex head unit and this is the salinity probe female port.

My probe looks like this:

The probe itself reads: Pasco Scientific 699-06621.

That's it. Cheers!

Hey Rimsky,

Do you experience the same drift with the Pasco?

The reason why I ask, is if this is a direct replacement for the apex conductivity probe, then maybe this isn't a viable solution. But if you're getting more consistency out of the Pasco then it might be worth it.

 

[Lbrdsoxfan]

Here is something that matters with info from the pasco probe: Accuracy is +- 10% which explains a LOT (I highlighted the relevant info on the card that came with the probes). Neptune never disclosed the accuracy IIRC.