The prime reason for Apex Conductivity Probe failures

[ThRoewer]

I think this is worth sharing here as well.

I had 2 of these probes failing on me.

Now, these electrodes are basically nothing more than two platinum ring contacts. So, unless it gets mechanically damaged or operated on a wrong amplifier, it should last a long time - if properly cleaned of course.

So I instantly had a hunch that the problem must be either with the cable or the connector. It turned out to be the connector or more precisely the solder joints inside the Mini-DIN connector. Whoever soldered these didn't know what he/she was doing and created cold solder joints. It is just a matter of time when these come loose or completely off. On the first electrode both leads had come off, on the second only one lead had come off (not that I would trust the other.)



A cold solder joint could also be one explanation why there are so many people reporting unstable readings or problems to calibrate the electrode.

The good news is that this issue can be fixed without shelling out over $120 for a new electrode if you can solder or know someone who can solder.

There are of course other issues with this electrode. One of them is that air bubbles might get trapped inside and alter the reading.