KH Director reading too high - tried a lot of the known fixes

[Row1974]

Vinny posted this

In addition to putting the filter at the end of the sample tube I found tiewrapping the filter in a 25mm pvc tee helped the consistency (and kept the filter where I wanted it)

Thanks, I'm happy with it now I've determined the calibration volumes by weight and results are as expected - less happy that I had to purchase microscales and I've used almost an entire bottle of reference fluid trying to work out what was wrong - in my opinion the documentation should reflect the importance of the calibration volume particularly the reagent and that the volume should be determined by weight