Hanna - thoughts on doing the "double test"

[ZoWhat]

I'm investing more and more in Hanna. Thinking about customizing the way I do testing.

Use one vial of just tank water to zero-out the unit and the second vial being the one with the reagent + tank water.

When running a test use 1st vial to zero-out and then 2nd vial to get reading.

BUT... rerun the test with the 1st vial to zero-out but turn the both vials to a different part of the vial glass to make sure a dirty or scratched or stained vial isn't producing an inaccurate reading.

Both test runs should be almost identical in #s within reason of the reagent "time-aging" in the 2nd vial

If I get whacky readings, consider buying brand new vials. (And yes I've researched that aging vials can be way off due to scratching and staining), I believe the standard is to buy new vials in between 6mos to a year. Past a year, the vials are too stained to be accurate

Thoughts?


.

 

[jgirardnrg]

I use a single vial to avoid differences that may exist between the vials. When done, I rinse clean with RODI and then store them filled with RODI.

 

[Gtinnel]

I've never done it that way but I have heard of others who have. You probably could partially rule out vial differences by doing a test the traditional 1 vial method and then doing a test with the two vials and see if you get the same result.
Is the only advantage of using 2 vials that you can test the vial with reagent multiple times?