Strange conductivity probe readings

[hemoi]

Hi All,
I have a strange issue with my conductivity probe.
Scenario:
About 3 weeks ago, i had a power outage. After the power was restored, my conductivity probe has behaved strangly. As you can see in the image, it is behaving more like a PH probe.
Prior to this my conductivity was stable.

Things I have tried so far:

1. recalibrated probe - same result
2. Tried a brand new probe. Same result
3. Re-installed firmware on P3 current version 5.11
4. Relocated "all" probes away from any other electrical interference. All probe cable are cabletied together. Since the cables are shielded it should not be a problem ?


Current probe settings (see image):
ADC 1: 20
ADC 2: 461


If anyone else has had this issue and resolved it can you please let me know.

Kind Regards,
Hemant

[Matthias]

are the readings outside the tank, e.g. in a cup of water, constant?

is the temp reading correct?

[hemoi]

Hi Matthias,
I have done some further testing:

The temp readings are correct.
I have also put all the probes into a seperate container of "fresh" NSW.
The Cos probe is now reading 2.0ms regardless of where i put it ?

Also a point to note: when I had the power outage, even though the profilux is connected via a UPS. The powersupply for the profilux broke. I replaced it with a 12v 1.0a supply. The original was a 12v 1.5a could this be another indicator ???

Regards,
Hem

[hemoi]

Update:
* I have replaced the Cos probe with a new one.
It still fluctuates a lot. I have attached an image of the graph showing the readings were stable until the power outage....
Also I am not able to keep a stable communication now with the unit over ethernet. I get an "Error 50" message. Is it possible that the profilux is damaged in some way ??

Please help !!

Kind Regards,
Hemant.

[Matthias]

a damage, maybe caused by the power surge, is possible

[Matthias]

or maybe the power supply you are using now is bad - we need a grounded PSU with a stable voltage

it is possible that electromagentic noise of a bad PSU affects the readings and the communication

[hemoi]

Hi Matthias,
I replaced the power supply yesterday and things seem to be reading better now. The Cos readings appear to be stable (so far).
Thanks for your help.
Regards,
Hemant