Hi, I have found the best way to get air out of filter is have the filter close to doser head and whilst running sample doser keep flicking the filter after a while no more air bubbles .
My first probe lasted aprox 12 weeks, like yourself had to prepare measurement cell to get a reading until probe failed. In the mean time I used ghl ion reference fluid only to find the results to be way out. Opened ticket with ghl , followed instructions including screen shots of voltages.They then informed me I could send the probe back to be checked under warranty. After reading the warranty I decided not to pursue as it is a get out on almost all paragraphs. I may be being unfair to ghl but they seem put all responsibility on the user and accept none themselves.
Still had bad results compared with hanna and triton icp...magnesium close but calcium way off, ion said 480 mg when in fact well over 600mg !
I found that the connection to unit for the probe sensor needed tightening, so please check this nut !
Air ingress seems to damage the probe quickly. Now on 3rd probe but now the ion is dead as the internal pipe blew off due to a slight blockage in sample pipe , don't know how this happened as it has a relatively new filter on.
Yes I opened it , because I have no faith in ghl warranties. And was surprised that there is no protection for the electronics if there is an internal pipe failure. Inside the sample pipe has a y connector that joins the waste pipe at the rear. This is what failed on mine.
Waiting to hear if they will sell me a new board, if not will try to find a good electronic repair shop.