Reagent pump not kicking in for kh director

[arvind]

I just got the unit repaired by GHL. I am trying to run some tests and I don't see the pump used for reagent is not running during the test and measurement comes as 0. Any idea what is happening?

I have asked GHL for help as the unit was just repaired by them but wanted to find out if others had similar issue.

 

[Billldg]

First you can try and take the pump dead off and make sure no debris is stopping it from running.

@Vinny@GHLUSA
@Ditto

 

[arvind]

First you can try and take the pump dead off and make sure no debris is stopping it from running.

@Vinny@GHLUSA
@Ditto

Pump itself running fine on its own. Just that it is not being activated when measurement is taken.

 

[Billldg]

Pump itself running fine on its own. Just that it is not being activated when measurement is taken.

I will take a stab at this, I would check the setup of the programming of the KHD. Please, amuse me, and check to see if the setup was somehow deleted or influenced. I am just taking a stab beyond the pump cleaning. We will get this figured out, no doubt.

If the pump works fine otherwise, then something is not triggering the pump during a KHD reading, and thus, me saying to look at the programming to make sure it knows which pump to look at when doing a reading.

@Vinny@GHLUSA

 

[wmb0003]

I am very surprised at a zero measurement. If the reagent wasn’t being pumped in, I would thing the measurement would time out and would error out instead of giving you a value.

The reagent pump also moves at the lowest/slowest setting; when I first set mine up, I thought it wasn’t going but upon further inspection, it was just moving extremely slow and quiet.

I would check the programming as Bill suggested and maybe also check to ensure the ph probe is calibrated because in theory if no reagent is being pushed in, the ph shouldn’t change.

 

[arvind]

Sorry not clear where should I check for programming. I thought all I have to do is click on check measurement now.

Also I notice the ph value is showing a very strange number. See the screenshot below.

 

[wmb0003]

I think what Bill was saying was check to see what dosing pumps are assigned and make sure they match up with how you have it setup(see below screen shot); I’m still kind of new at this GHL stuff but I bought a used KH director and had some issues with it when I first set it up so I did a lot of trouble shooting with similar erroneous reading.

That ph reading and ADC1/2 values don’t look right to me. When you sent the unit in for repairs, did you send them the ph probe also? I had to get a new ph probe with mine because I suspect the previous owner stored to probe dry. I was having similar crazy reading from my probe.

 

[arvind]

Gotcha. All those pump assignings look good to me. I did send in my probe along with the unit and they told me that the probe is in good shape so don't need to replace it.

 

[wmb0003]

Gotcha. All those pump assignings look good to me. I did send in my probe along with the unit and they told me that the probe is in good shape so don't need to replace it.

I would try to recalibrate the ph probe but I think the calibration only determines your ADC values so not sure if that will do anything but it’s worth a shot. If your ph probe is reading those crazy numbers I think something is up with it. I would create a ticket with GHL if you haven’t already.

 

[Billldg]

Sorry, at work, but you check it in GCC like when you originally install it.

@Vinny@GHLUSA

 

[Andy Reed]

Hi,

Sorry reply to an old thread but wondering if you found a solution to this. My KHD has been running perfectly for 5 months but last night started to do the same. Now reading zero and no longer activates the reagent pump during a test. Config looks fine and reagent pump manually activates ok.

A single test used to take 13 minutes but now finishes early after 7 minutes.

Cheers,
Andy.

 

[Lasse]

Hi,

Sorry reply to an old thread but wondering if you found a solution to this. My KHD has been running perfectly for 5 months but last night started to do the same. Now reading zero and no longer activates the reagent pump during a test. Config looks fine and reagent pump manually activates ok.

A single test used to take 13 minutes but now finishes early after 7 minutes.

Cheers,
Andy.

Have you check if it is your pump head that not works properly. Disconnect the reagent tube into the KH director and lett the tube go down in a cannister instead. Try to run the pump manually and see if it works. Sometimes - the plastic in the pumphead cover breaks and block the pumps action. It can help to run it backwards. use the app for manually running - check the reverse and press the dose tab and hold it down and see if it starts to go backwards.

If so - take away the cover and repair or shift it out.



Sincerely Lasse

 

[Bleigh]

I literally spent the past 3 hours Trouble shooting the same issue. I solved it and wanted to add it in case anyone else dealt with it.

Symptons: khd wasn’t pulling any reagent. It would flush the cell and empty the cell with no attempt to measure. There was no issue with programing. The test would read 0. I finally realized that the initial ph was starting in the 3 ph range, which is incredibly low. I decided to calibrate the probe. When I pulled it out, it was quite dirty. Some type of sponge or bacteria had grown on the end.

Solution: I cleaned the probe off, and calibrated it. I am currently running a test and the reagent pump is now working. The initial ph started in the high 7’s.

Take away: I assume that if the initial ph starts below the titration set point, the khd doesn’t run a test and returns an alkalinity result of 0.

 

[LOVEROCK]

I literally spent the past 3 hours Trouble shooting the same issue. I solved it and wanted to add it in case anyone else dealt with it.

Symptons: khd wasn’t pulling any reagent. It would flush the cell and empty the cell with no attempt to measure. There was no issue with programing. The test would read 0. I finally realized that the initial ph was starting in the 3 ph range, which is incredibly low. I decided to calibrate the probe. When I pulled it out, it was quite dirty. Some type of sponge or bacteria had grown on the end.

Solution: I cleaned the probe off, and calibrated it. I am currently running a test and the reagent pump is now working. The initial ph started in the high 7’s.

Take away: I assume that if the initial ph starts below the titration set point, the khd doesn’t run a test and returns an alkalinity result of 0.

What do we use to clean the probe

 

[Bleigh]

What do we use to clean the probe

I use a lab tissue with no lint and rodi water in a lab squirt bottle. Some times I pull out a q tip.

 

[Lasse]

I use a lab tissue with no lint and rodi water in a lab squirt bottle. Some times I pull out a q tip.

I´m harsher - I use a soft toothbrush and if it is on the return trip of its lifespan - I soak it for a while in 3M KCL solution

Sincerely Lasse

 

[Bleigh]

I´m harsher - I use a soft toothbrush and if it is on the return trip of its lifespan - I soak it for a while in 3M KCL solution

Sincerely Lasse

Lol. I’m sure being more harsh isn’t a problem. I’m probably way to cautious from the many years of working in labs with super expensive probes.

 

[Lasse]

I have been working with industry standard online pH electrodes for many years. The environment they normally work in is much more harsh than a toothbrush During these years I found that an old hobby electrode from Dupla (they do not exist as sole brand today and the ones that sells under the name Dupla today - is not the same) was outstanding compared with many other industrial grade electrodes. The one GHL have today looks like the old Dupla model and have used it in heavy loaded Fish Farms system with good result - but the tooth brush is essential in these systems.

Sincerely Lasse