Conductivity probe broken?

[aleonn]

I had my conductivity probe in storage for the last few months, and had time to attempt installation recently.

The first step was the dry calibration, and the number settled quickly at 44 (within half a second).

The second step, I calibrated with 53us solution, but the number stayed constant at 44 and never changed. There's no change whether I place the probe in RO water or tank water. When I press "OK", the controller states that the calibration failed and will use the default settings.

When I place the probe in the sump afterward, there's a constant reading of "01.2," whether or not the probe is in the sump, in RO water, or dry.

* My Apex firmware is: 4.04_BC10
* My PM2 SW revision is: 003 (OK)
* Temperature and pH probes are working fine, and are attached to the base unit.
* Cleaned the probe with vinegar and RO water
* Resetting the Apex did not help

Has anyone else experienced this issue before? The probe worked a few months ago, and is about 4 months old. My understanding is that I did not have to store the conductivity probe with any particular storage solution. What may have caused this?

 

[aquamanic]

Have you enabled the probe via the display module: Setup - Cond Setup - Cond enable

 

[aleonn]

Yes, it is enabled.

 

[Jocko]

You used it before? It is dirty? Try cleaning with vinegar or something. Maybe the contacts are covered in some dried gunk.

 

[aleonn]

I've used it before with good results. I cleaned the contacts with a toothbrush as well as a vinegar soak. Very strange

 

[rbredding]

do you have an additional temperature probe connected to the module for compensation?

(curious as to whether that could be an issue)

 

[aleonn]

I do not have a temp probe attached to the pm2 module. So temp compensation is off

 

[coralreefhq]

I had the same problem setting it up as well.

There were a lot of complications dipping it in the 53us.
It didn't work after 4 tries, so I left it at a default.
Waited for 10-15 mins for the numbers to settle in the solution.
Forgot what number I set it to, but when I tried to update it, it restored to default settings as well.

I bought mine brand new, figured it was good to go out of the box, but I calibrated it either way.

Right now it is reading 29.5 Condx6, tempx6 is 76.8.
I do have a secondary Temp probe, as well as a PH probe.

Tagging along to see how this can be corrected, my probe is brand new, bought it this past Friday.

 

[Tomkodet]

The Apex has 4 Cond/Salinity Ranges. Be sure it is either set to "High" or "Salinity".

FYI - I just bought my Cond probe this week. It calibrated properly and when put back into the ref solution read a perfect Salinity of 35. However, over the course of hours it always seemed to drift lower. After discussion with Apex, we think it is bubbles accumulating on the probe sensor. Apparently as the bubbles accumulate, the sensor slows looses surface contact with the water and the reading decreases.

A quick shake of the probe underwater will return it to a predictable value. Has anybody else seen this?? any ideas how to fix it??