P4 conductivity probe read less every day..

[decena]

Yes - I agree to the microbubble theory :-) But can anybody explain, why in my case the IKS conductivity sensor is reading correct values (mounted in the same holder 2cm away) - with microbubbles?
The IKS module is ten years old!!! And works correctly from the beginning.

I assume, that it has something to do with the way the probe is build.

The IKS probe is mounted in a PVC fitting and the sensor plate is realy big (2x1cm). Also the sensor plate is mounted in a 45degrees angle to the pvc fitting. Above there are air holes (now I am knowing why there are "holes" :-) ). The fitting has a diameter of 4cm. I have never understood why - until now... If I put the sensor horizontaly/ parallel to the overflow - I have the same behavior like the PL4 with the IKS.
The bad thing ist, that this module can not be used with the IKS (because it´s the first generation without BNC coupler and with integrated circuit box).
In this moment, I am printing an comparable housing/ holder for my sensor including a bubble trap with my 3d printer.
Hope that helps. I have no more options in the sump to prevent micro bubbles.
As i have ordered the PL4 my hope was, that I will benefit from the last 10 years of eveleopement, IKS has missed.
Seems that I was a way to optimistic.

Could you please show a photo?

[dawsokj1988]

I still haven't figured out the solution to this. I've tried moving the probe around to various locations, with no success. Does anyone currently run the P4 with the probe cell? Could you post your salinity measurements? Here's mine.Screenshot (481).jpg The spikes upward are when I pull the probe out of the water and put it back in.

[decena]

I still haven't figured out the solution to this. I've tried moving the probe around to various locations, with no success. Does anyone currently run the P4 with the probe cell? Could you post your salinity measurements? Here's mine.Screenshot (481).jpg The spikes upward are when I pull the probe out of the water and put it back in.

+1. I hope someone has run the probe cell and can help us.

[Matthias]

we had this topic, decreasing conductivity reading over some time, in the German part of this forum, too

we contacted these customers directly to find out what is going on, the results were:

- electronics and firmware of ProfiLux 4 is 100% OK
- changing the probe - EVEN FROM OTHER MANUFACTURERS! - didn't change the situation, after a few days the value fell again
- and now the most interesting part: only tipping the probe very slightly (without removing the probe out of the water!) recovered immediately the correct reading

-> we assume that there are micro bubbles which have disappeared when touching the probe

one customer dislocated the probe a bit and it seems his problems had gone

I think the sensor should be somewhere where more flow is, to remove potential air

PS: Reading this thread may give the impression we would have here a general P4 or even GHL problem. This is NOT true.
We have here some cases, but on the other hand we have meanwhile > 1000 P4 users WITHOUT problems.
AND: we are using these probes UNCHANGED for many years now, it is not correct to say these probes had a general problem

-> please try the probe somewhere else - I am not sure which tactic is better: a place with less flow and maybe less bubbles or more flow which removes the bubbles

[Vinny]

we had this topic, decreasing conductivity reading over some time, in the German part of this forum, too

we contacted these customers directly to find out what is going on, the results were:

- electronics and firmware of ProfiLux 4 is 100% OK
- changing the probe - EVEN FROM OTHER MANUFACTURERS! - didn't change the situation, after a few days the value fell again
- and now the most interesting part: only tipping the probe very slightly (without removing the probe out of the water!) recovered immediately the correct reading

-> we assume that there are micro bubbles which have disappeared when touching the probe

one customer dislocated the probe a bit and it seems his problems had gone

I think the sensor should be somewhere where more flow is, to remove potential air

PS: Reading this thread may give the impression we would have here a general P4 or even GHL problem. This is NOT true.
We have here some cases, but on the other hand we have meanwhile > 1000 P4 users WITHOUT problems.
AND: we are using these probes UNCHANGED for many years now, it is not correct to say these probes had a general problem

-> please try the probe somewhere else - I am not sure which tactic is better: a place with less flow and maybe less bubbles or more flow which removes the bubbles

We've also conducted a test on an established system and have found no drastic changes in Conductivity.
P4 Conductivity readings.jpg

[totorus]

Hi vinny
I also like the others I have problem .. I recalibrated probe and moved on the other side with strong flow ...
To me also to incorrect salinity values ...
Tonight rewind all new calibration and move again probe into another area. And wait 2-3 days to see if anything changes.

[Vinny]

Hi,

Since these probes are very sensitive to micro bubbles, it would be best to place it in an area where you do not see micro bubbles developing from the tank's drain setup or skimmer. Skimmers can also release some micro bubbles over time. Depending on the direction of the flow and probe placement, these bubbles can travel in the direction of the probe and get trapped before they reach the surface. Perhaps positioning them in an angle will help provide a more stabilized reading.

In our test setup, we have the probe positioned in the same compartment as the return pump, just tucked away in the corner. This area does not have any drain plumbing and is in an area that I would consider to have moderate flow. Enough that no air bubbles develop as water travels over the sump baffle walls.

[dawsokj1988]

- electronics and firmware of ProfiLux 4 is 100% OK
- changing the probe - EVEN FROM OTHER MANUFACTURERS! - didn't change the situation, after a few days the value fell again

This test only eliminated one of the variables, not both. Other sensor probes were hooked up to the PL4 with the same result, which implies it could indeed be the PL4 causing the issues, not the probes themselves.

I would still like to believe that microbubbles are causing this. I've tried several locations within my sump, including high flow areas and low flow areas, with no general improvement on the drift. I don't mind purchasing the cell to house the probes, I'm just trying to look for confirmation that this will indeed solve the issue.

Also, generally speaking, less than 10% of a consumer base actually participates in forums. A smaller number of that subsect actually posts (where a lot of people just read the forums looking for solutions). When multiple (over 5) people actually post about the issue, that most likely translates into a larger population encountering it.

I'd also like to mention that I'm overall very satisfied with the PL4 and the Doser 2.1. It's just these little issues I'm looking to solve.

Cheers!

[Matthias]

the electronic circuit of the conductivity probe port is identical to the P3 and the expansion cards (there was no need to change a perfectly working system), I have problems to understand why the P4 should behave then different

but we are aware that here is a problem for some users and believe me, we want to solve this as soon as possible

we have to consider all possible options, even a bad batch of probes (although the manufacturer already said he doesn't believe this)

-> I think here helps only direct personal support


To all customers with this conductivity-issue

please contact us directly and let us go from there:

USA: info@ghlusa.com

all other regions: info@ghl-kl.de

[decena]

Hi, I think I've solved the problem.. I'm not sure, but in the las 24 hour the probe is reading the same. It doesn't read less every hour as before. I haven't changed the position of my probes, it's on the same place. But I have installed a new flow pump (small) "Sicce Voyager Nano 1000 l/h".The pump is at a distance of 20 cm. And the most important detail (I hope I can explain this correctly, I don't know much English):

- The flow is in the same direction as the probe slot. I attach an image, but if you have any doubt please ask me. In the next two days I am going to watch it to confirm if I'm right.

IMG_1359.jpg