Salinity probe influenced by intermittent EMI

[taowa]

Anyone experienced Salinity probe being influenced by intermittent EMI before?

My salinity's reading wrong number. I got support from Neptune to remote to investigate but Neptune informs me that it's because of intermittent EMI.

What I doubt is
-After I calibrate, I try by
1. Putting probe in test solution, it's reading correctly.
2. I take the water from my tank and put in a cup. I test using water in the cup but it's reading wrong number. This's what I confuse since water in the cup should be isolate from intermittent EMI, why it's still reading wrong number?

 

[slief]

Anyone experienced Salinity probe being influenced by intermittent EMI before?

My salinity's reading wrong number. I got support from Neptune to remote to investigate but Neptune informs me that it's because of intermittent EMI.

What I doubt is
-After I calibrate, I try by
1. Putting probe in test solution, it's reading correctly.
2. I take the water from my tank and put in a cup. I test using water in the cup but it's reading wrong number. This's what I confuse since water in the cup should be isolate from intermittent EMI, why it's still reading wrong number?

What number is it reading when you put it in the cup of tank water? What is the salinity of the tank water? What are you using to measure the tanks salinity? If a refractometer, how are you calibrating it?

 

[seldon]

Also, how are your wires routed? Are you making sure you get the air bubbles out of the probe when you calibrate or while in the cup?

 

[taowa]

What number is it reading when you put it in the cup of tank water? What is the salinity of the tank water? What are you using to measure the tanks salinity? If a refractometer, how are you calibrating it?

I use 2 refractometers to compare and also bring water to have my friend test. Only Neptune got wrong number.

What's weird is after I calibrate,
I put probe test solution, it reads correct number
I put probe in my tank, it reads wrong number
I put my tank water in a cup and probe in a cup, it reads wrong number

I do calibration many times with Neptune support remote to my home

 

[taowa]

Also, how are your wires routed? Are you making sure you get the air bubbles out of the probe when you calibrate or while in the cup?

I calibrate more than 10times. Very sure no bubbles in probe. What do you mean about wires routed? Don't think my Neptune wires different from others since I'm using it more than 2 years

 

[Antipodes]

I calibrate more than 10times. Very sure no bubbles in probe. What do you mean about wires routed? Don't think my Neptune wires different from others since I'm using it more than 2 years

So this is a recent problem?
If so when did this new problem start?

And what the intention meant for cable routing is.
Does it run next to or within 6" of power cables or any lighting cables, or steel framing.

If you have installed new or different lights these can sometimes cause EMI problems.

Do you know someone who has a Apex who can test the probe for you. It could be damaged probe wiring so that the shield is not working correctly. (Low likely hood)

If you have residual EMI all the time, when you calibrate it will also be affected by this EMI and provide an inaccurate calibration.

 

[taowa]

Yes. It's recent problem.
It's just start one day. I didn't change anything recently.
The Main module is next to Energy Bar since beginning. So all lighting&pump cables are at Energy Bar. I don't use steel frame.

The shop lent me another new probe to test but same wrong result.

So this is a recent problem?
If so when did this new problem start?

And what the intention meant for cable routing is.
Does it run next to or within 6" of power cables or any lighting cables, or steel framing.

If you have installed new or different lights these can sometimes cause EMI problems.

Do you know someone who has a Apex who can test the probe for you. It could be damaged probe wiring so that the shield is not working correctly. (Low likely hood)

If you have residual EMI all the time, when you calibrate it will also be affected by this EMI and provide an inaccurate calibration.

 

[TerenceF]

What changed in your tank, equipment-wise? What pumps do you run?


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[seldon]

I had a similar issue, but with mine the salinity would fluctuate inversely with the ramp on my lights. I had a second PM2 setup that would hold rock solid. I changed the routing of my wires, changed salinity probe and replaced the aquabus cable. In the end it wound up being the PM2 module itself. Apparently it had a weak IC in it that was more susceptible to EMI. I got a new PM2 and the reading is now just as solid as the other.

 

[taowa]

What changed in your tank, equipment-wise? What pumps do you run?


Sent from my iPhone using Tapatalk

I didn't change anything. I have 4-5 brands of pumps from China to German

 

[slief]

I didn't change anything. I have 4-5 brands of pumps from China to German

You can do one of two things to hone in on the issue. Shut everything off in your tank but the Apex and turn one device on at a time until you determine which device is causing the issue or turn one device off at a time until you find the source of the EMI. It's likely one of your pumps but it could be the result of a light ballast, power cable etc.