Hi,
I have been running my Profilux 4 since Jan. this year.
Everything works OK except the following.
My slainity probe (conductivity probe) readings drift so fast in thease days.
It was almost OK until couple of weeks ago.
It suddenly drifts downward from 34.0 psu to 31.2 psu within a week.
I measured actual salinity with a Veegee refractometer and Hanna salinity (conductivity) instrument just calibrated with reliable reference fluid.
The results are very stable within +/-0.1 psu.
I cleaned it with vinegar/rodi 50/50 for 30 minutes, and recalibrated. But it is same.
Is there any other remedy measure to take it back to normal?
Or do I have to replace the probe?
Thanks in advance.

Son