Quote Originally Posted by Yosh01 View Post
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?