KH Director Measurement Problem

[chivas_reef]

Hello All,
I got a Kh director at the beginning of May and everything was great, but after 2-3 weeks I started having problems with measurement. I take 2 measurements a day.
When kH is 8 I get measurements like 11 or 5. :/
After cleaning and calibrating the dosing heads 2 times, I realized this. The waste water dosing head cannot completely empty the measuring cell. The same goes for the "sample water" tube too. Always remains test water in cell and tubes....
Even with the "Empty measurement cell" command, the test water in the hoses cannot be completely drained.
I think that the reason for the deviation of the tests is the remaining water, but why do you think the 1st and 3rd dosing heads cannot empty this water?
Has anything like this happened to anyone before?

 

[Lasse]

The sample tube is emptied backwards. If it not will be emptied totally - the tube volume or/and the calibration of head 1 is wrong. Check the filter for clogging too.

Sincerely Lasse

 

[chivas_reef]

The sample tube is emptied backwards. If it not will be emptied totally - the tube volume or/and the calibration of head 1 is wrong. Check the filter for clogging too.

Sincerely Lasse

Hello Lasse,
Thanks for the suggestions.
But I had already checked calibrations for all heads. They are working flawlesly on calibration state.

 

[Lasse]

Are your tube volume right? If you use a filter (their original) you should add 7 ml to the calculated tube volume.

Sincerely Lasse

 

[chivas_reef]

Are your tube volume right? If you use a filter (their original) you should add 7 ml to the calculated tube volume.

Sincerely Lasse

Hello Lasse,
Yes, I calculated. Not even with the hose length.
I filled the entire sample tube with water by operating it manually.
Then I took the tip of the sample tube out of the water. I weighed the water in the sample tube with a precision scale.
I really can't find where I went wrong. I even plan to measure the volume of the hose again.
Do you think it could be a problem with the vent port? If the vent port does not get air, I think it cannot drain the water due to the vacuum. But It is a long shot.(Because of this possibility, I put the vent hose in a big mouth jar and nothing has changed.)

 

[Lasse]

Now we have reached my level of incompetence I´ll think you better open a ticket or maybe @Vinny@GHLUSA can help.

Sincerely Lasse

 

[chivas_reef]

Thanks Lasse,
I've been talking to Vinny via ghl support page. Since I was wondering if it has happened to anyone else on the forum, I wanted to ask here as well.
Any other guesses/suggestions?

 

[Ditto]

Is the Vent Dosing tube out of Water? it can not be submerged at all?

My Vent Tube does not empty completely because it is longer then sample tube line.

Did you check your inline filter for the sample line is it clogged?

 

[Lasse]

Thanks Lasse,
I've been talking to Vinny via ghl support page. Since I was wondering if it has happened to anyone else on the forum, I wanted to ask here as well.
Any other guesses/suggestions?

I have got **** values too but not any variation between too low and too high values - more like 7, 7, 7, 9, 7, 7 or 7, 7, 7, 5, 7, 7 The situation when I get to high readings - I suspect that too much sample water have been sucked in - and the opposite if I get a low **** value. Its a titration - hence if it a too small value (than the expected) - there has been to little sample and the opposite if it is a high error

Sincerely Lasse