Which one do I trust?

[eric33014]

So have a trident and dkh has been reading steady 9-9.25, I am dosing and it has been that level for months. So today I said why don't I try my Hanna dkh and see where things are. I have not double checked anything since I got the trident 4 months ago. Hanna gave me 10.0. Which one do I trust is giving me the more accurate result consistently?

What would you do?

 

[Saltyreef]

Look at each of these devices specs and read the accuracy value.
Use the one thats +/- less than the other if the resolution is the same.

Could be reading the same but one device has less tolerance.

Also, take 3 consecutive tests from each and average them.

 

[Timfish]

Do a search for making a alkalinity standard then like Saltyredf said do multiple tests tests against the standard and average them out to see which is more consistant. Also, when getting new reagent test it against the old reagent to verify consistancy.

 

[nereefpat]

Those values are pretty close. You could just call it about 9.5 dKH