HI 736-25 Phosphorous Ultra Low Range (ULR) Reagent Lot H 025

[Pistol]

[quote author=Pistol link=topic=7589.msg84934#msg84934 date=1394235343]
I'm now convinced that lot 30 is defective, the reagent is more like granules than powder and it doesn't dissolve completely, even after the test with vigorous shaking.

Are you using 3 seperate reagents ? One for each test?
[/quote]Yes, right now I have lots 27, 30, 34. Lot 34 is powder and dissolves good but the readings are all over the place, 30 ppb difference between tests, I've had 2 or 3 other lots but can't remember what numbers, one was 25 I think. I'm ready to pitch it in the garb but I guess i'm wishfully thinking hanna will fix the reagents....... Maybe I will sell it to some unsuspecting smuck, just kidding.

 

[Boga]

Merk has standard solutions for everything... Total phosphorous is within the range of the checkers if I remember correctly but my current workplace doesn't use it.  I can ask around, I think a bottle goes for around $30.  Perhaps the lab at Harleymike's place has it in stock?

Thanks. Maybe I should ask Hanna Instruments what they are using for "calibration". There could be an issue of verifying a "marine" checker with non-saltwater standard. Just thinking loud ...

 

[unibob]

Any updates on this?


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[Petercar (RIP Dec 2017)]

let me check what i get with my hanna with lot 25. amd the new milwaukiie tester i got

 

[reeffreak]

A lot of work for a checker that should make life easier. Solution, toss it in the garbage

 

[Boga]

Hanna's technical support pointed to HI 725-11, but I think it is for colorimeter only. I don't think it acts as a standard phosphorous solution. Anyway, it was mentioned that "they were not the most accurate standards".

https://www.reefsupplies.ca/online-store/Hanna-HI-736-11-Calibration-standard-kit-for-phosphorous-tester.html


About lot #25, there is no official response, yet.