Quote:
Originally posted by Boomer
It looks like the test value you guys for PO4 is off and they are working on it. Meaning, your PO4 is lower than what they state for your water.
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Interesting. I have a Hach portable spectrophotometer (the mid-range model, I think it's model 850). I checked the unit against Hach's phosphate standard solution shortly after I got it. I found the MDL for my technique to be about 0.02 as it was able to detect that concentration in 3 out of 3 tests. The measurements ranged from 0.01 to 0.03 on those samples.
I drew a water sample and sent part to AWT and the other I tested with my kits and spectrophotometer. I measured my PO4 at 0.12, (it usually runs high at .03 to .07), but then their results came back as 0.01. If their test result is right then my meter is now off by a factor of 10 while I previously found it to be accurate to +/- 0.01 (a factor of 1.5) at the low end of its range. Unless my meter has drifted (I plan to recheck the calibration) their results are way off.
Allen