Hanna help

[DannyB]

So I seen to be having issues with my new Hanna ulr phosphorus checker. A few days ago I used it and had a reading of 37 ppb and today my result was 2ppb. So I thought this ridiculous and retested, 0ppb.


Is it possible to get this kind of reading, the phosphates are being used up, or am i doing something wrong?


Thanks for any advice.

 

[DannyB]

bump

 

[saltyhog]

Somethings up for certain. If I repeat test I rarely get a result more than 1-2 ppb different than the original.
Are you:
1. Holding the button for 3 seconds to trigger the 3 minute countdown after the C2 (adding the reagent)?
2. Making sure all the bubbles are out of the vial before zeroing (C1)? Making sure all fingerprints are off of the vial?
3. Orienting the vial the same way each test (I line the "10ml" up with the latch)?

I set the timer on my smart phone or watch for 2 minutes to mix the reagent. I only mix by inverting the vial between my thumb and index finger (back and forth at about a once every 2 -3 second clip).

Other than that I got nothing! Maybe a defective unit?

 

[DannyB]

I haven't oriented the vial the same way each time. I will try that.