KH Director and Reference Solution help

[bhuyett]

Hi everyone,

I have been through quite the ride with my KH Director and some issues that cropped up while I was travelling. Fast Forward, I'm now finally mustering up the nerve to bring it back on line and wanted to use the KH Reference Solution to calibrate the KH Director to validate that it is testing accurately.
After calibrating the Dosing pumps, and the probe first. I then proceeded to run a test with the REF solution. When it completed the task it displayed 8.2dkh. As suspected the tests seem to be testing higher than the Reference. The bottle says +/- 0.2 of the 7.5dkh, so I would assume that would mean 7.3dkh - 7.7dkh if all things are correct.

I've measured out my WASTE Water tube 79" + Doser tan tube 4.7" + dosing tube from 2.1 doser to KH Director 6.3" = 90" total length of the Waste Water tube. I've entered the following into the Tube volume Calculator:
4mm Inner Diameter
90" Length
Calculated Volume = 29ml with an 80ml sample (max volume allowed)

Would anyone know what I should look at next to understand what I can do to get closer to the Reference Solution?

Any help or insights would greatly be appreciated.
Thank you,

 

[Kyl]

The calc is for the sample tube length, not waste.

 

[bhuyett]

Sorry you are absolutely correct and what I mean. I confused the two.

 

[Brew12]

Hi everyone,

I have been through quite the ride with my KH Director and some issues that cropped up while I was travelling. Fast Forward, I'm now finally mustering up the nerve to bring it back on line and wanted to use the KH Reference Solution to calibrate the KH Director to validate that it is testing accurately.
After calibrating the Dosing pumps, and the probe first. I then proceeded to run a test with the REF solution. When it completed the task it displayed 8.2dkh. As suspected the tests seem to be testing higher than the Reference. The bottle says +/- 0.2 of the 7.5dkh, so I would assume that would mean 7.3dkh - 7.7dkh if all things are correct.

I've measured out my WASTE Water tube 79" + Doser tan tube 4.7" + dosing tube from 2.1 doser to KH Director 6.3" = 90" total length of the Waste Water tube. I've entered the following into the Tube volume Calculator:
4mm Inner Diameter
90" Length
Calculated Volume = 29ml with an 80ml sample (max volume allowed)

Would anyone know what I should look at next to understand what I can do to get closer to the Reference Solution?

Any help or insights would greatly be appreciated.
Thank you,

I've found that I do not get an accurate reading for a test or two after calibrating the dosing pumps. I suspect it is from a small amount of air that gets in the line during the calibration.
Now, I run 2 tests on my tank after I do my calibrations and then pull a sample on the reference solution. I've been much more successful this way.