KHD calibration

[TCoach]

I have some alkalinity calibration standard reagent that is 7.0. I ran 4 tests and each test ended up being 0.1 d KH lower than the prior. Any reason for this? It has me concerned that using an unchanging standard, the results kept going down.

Any idea what is going on here?

Thanks,
-Chris

 

[TCoach]

P.S.

I calibrated the KHD probe within the last week.

 

[Vinny@GHLUSA]

Looks fine to me.

When testing with a reference solution, it's important to consider the tolerance of the KHD and the reference solution. With both, the total tolerance becomes +/- 0.4 which means the numbers you saw are still within that acceptable range.

 

[TCoach]

Looks fine to me.

When testing with a reference solution, it's important to consider the tolerance of the KHD and the reference solution. With both, the total tolerance becomes +/- 0.4 which means the numbers you saw are still within that acceptable range.

Thanks for clarifying! Should have known that. Guess I'll blame it on the holiday weekend.