See and I was going to be more biased and say... "proof that the trident is off!"
In all honesty, the trident shows a lot bigger swing throughout a 24h period.
I know that it's using a rubber ruler, but when I see a significant drop or increase with the alkatronic, I bump it against hanna and it's always within 0.3 dkh.
There's no doubt that both units use an algorithm to determine the readings based on previous tests in order to minimize outliers. I also wonder which one is more correct?
The trident had been on track with alkatronic before I switched to DIY. Both of them were consistent with the hanna checker. So something about the reagent or the reagent tube I had to replace causing issues.

