Hanna high rang reagent weight, good to know...

[Patx]

Good to know when changing batch.
Hanna high range. HI782

Last box my water was testing around 25ppm
New box result are in the 29ppm. (+4ppm) (not a big deal, but still)
Probably less difference in lower ppm value (i suppose)

I always use a scale 0.00grams. To fill the cuvette to 10grams.
Open the reagent/start timer 2:00 minutes, poor reagent in bottle.
Shake until ~1:50 minute and press at the 2minutes mark.

Last batch, reagent that fall in the cuvette weight 0.20-0.21grams (25ppm zone)
New batch is more in the 0.26 zone... (30ppm)

The phosphorus ULR HI-736 reagent is more precise whit a 0.17- 0.18 on all the batch i have in the past.

Just saying

 

[Randy Holmes-Farley Verified Community Expert]

Just an fyi, the amount of reagent or water added is not especially critical for a test like this.

 

[Patx]

Oh but...but...but lol
Test 10min. Appart
new batch always ~+5ppm vs old one.
And when less reagent use the results was more like 1ppm appart.

Well ok then, some random effects I suppose.