How to get accurate KH Director readings

Hi All,

I've tried to get in contact with the support of GHL, but I don't get any response. (ticket raised at 02/09/2021)
I´m hoping someone here has the knowledge to help me out?
I'm about to return my KH Director setup, as I'm really getting ********** with it.

My problem is I can't get a value out of my KH director which makes any sense.
The KH should be around 8, but after almost a week of recalibrating, measuring ml, reference fluid, etc, etc. I still don't have a working KH Director
I guess I've tried all the tips which I could find on the internet, but sadly still without the wanted result.
- Measured the sample water line with a metric cilinder. (23ml. Calculator said 26ml)
- Calibrated the sample water head with a metric cilinder (35ml/m)
- Calibrated the reagent head with a metric cilinder (4.2ml/m)
- Calibrated the waste water line (35ml/min)
- No bubbles in reagent line
- Tried to get a sensible reading with 7.0 dkh ATI reference fluid. (almost used 1000ml)

There is one thing I don't really understand.
The sample line should have no bubbles, but when the measurement is done the sample line is emptied by the doser, which eventually will blow some air in the inline filter.
When a new measurement is started the air which is trapped in the inline filter will cause air bubbles in the sample line....
This same air will also eventually end up in your waste water line...
How do you guys solve this issue?

At this moment at least I got 4 measurements in a row of 6 dkh, but I know for sure this should be near a 8 dkh (8.2).
Can anyone help me out?

How do the KHD results compare when you run 3 back-to-back tests with the 7.5dkH reference fluid?

Quote:

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Originally Posted by Vinny

How do the KHD results compare when you run 3 back-to-back tests with the 7.5dkH reference fluid?

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Hi Vinny,

I've opened a ticket and I guess I'm almost there. [Ticket #4472]
Probably you want the proceed in this ticket?

Hi there ,
I am having the same issue. We’re you able to resolve it?

Quote:

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Originally Posted by AnyaL72

Hi there ,
I am having the same issue. WeÂ’re you able to resolve it?

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Hi anyal,

Yes, I did, but it took me some time and a lot of patience...
I'll try to explain as good as I can.

First I've calibrated all 3 pump heads of the doser.

Then look at the doser while running a test.
First the khd will be filled to flush.
Then check if pump 3 will fully empty the khd of flush water.
If yes.
Check if the sample line amount is filled in correctly.
To sort of check if you have filled in the correct amount ml of the sample line.
When the test is done the water in the sample line will be pumped back into the sump.
When the line is empty the doser should also stop pumping just a little later.
If this is too long you know you've filled in too much ml.
If the line still has water in it you havent filled in enough and you should higher the sample line amount.
My experience is that the amount of the sample line doesnt really affect the reading as long it is close to the actual amount.
In my case 38 or 40ml doesnt change the outcome.

Run a couple of test to see if its at least giving you stable readings.
If this is the case.
Then fine tune the amount of pump 1 and 2 until you have a correct reading.
I just highered the amount of pump 1 and made sure pump 3 was always keeping up with this amount. And see what happend to the outcome. Was it higher or lower.
Then did the same with pump 2 until i got a reading which made sense.

So long stort short as soon you have a stable reading and this will happen when the amount of the sample line is close to the actual amount and pump 3 will fully empty the khd. Then play with the amount of pump 1 and 2 and always make sure pump 3 will empty the khd fully after flushing and testing.

I did the calibration all with ghl ref. 7.5 dkh and finally ended up with a reading of 7.3, so im very happy with the result.
Although next time i would only do the fine tuning of calibration with the fluid as it took me 2 liter of reference fluid to get the job done.

Hope this makes a little sense and will help you a little bit getting ot to work.
Otherwise feel free to ask more questions

I want to comment here.
Actually you don't need to "fine-tune" the doser calibrations. If the calibrations are perfect (see our support page / knowledge base how to do that) you will get perfect results.
If not there might be somewhere else a problem, there is a KHD troubleshooting guide on our support page.

If you still don't get the readings you expect you should rather use the "adjustment" setting to correct the show readings.

Quote:

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Originally Posted by Matthias

I want to comment here.
Actually you don't need to "fine-tune" the doser calibrations. If the calibrations are perfect (see our support page / knowledge base how to do that) you will get perfect results.
If not there might be somewhere else a problem, there is a KHD troubleshooting guide on our support page.

If you still don't get the readings you expect you should rather use the "adjustment" setting to correct the show readings.

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Hi matthias,

I have installed 3 khds, but was really struggeling on all 3 of them.
I thought it would get easier after doing it before, but sadly i was wrong.
I guess I followed the guidelines, (watched the instructions of the ghl YouTube videos and some other videos of khd users),but got strange measurements.

Playing with the pump heads got me close to the actual ghl ref. 7.5 value.
After some use I found out this wasnt the solution as the value of the reagent and waste water levels wasnt displayed correct anymore.

So today I resinstalled the setup once again.
I know 100% sure the pump heads are calibrated on actual values.
I've weighed ro water on a high precision scale and did that at least 5 times per pump head.
Pumphead 1 and 2 I did even more.
Pumphead 3 I just kept an eye on If it emptied the khd after flushing and at end of the test.
This gave me a constant measurement way below the 7.5 dkh of ghl reference.
I cant remember the exact value but it was everytime the same value within 0.1 dkh.
The solution was a measurement correction of 17% to get the measurement spot on 7.5 dkh.
Tomorrow I will sent in an ICP test to compare the result of that with the khds.

Please let me know if there is a better way to install the khd??
as I need to do this again shortly with another khd at a friend.
And probably the same will apply to the ion which I have in preorder.
The way I do it costs also a lot of refence fluid and reagent which isnt cheap.
To calibrate 3 khds i used almost 1 liter of reagent and 3 liter of reference fluid.
This should be done easier, right?