YSI 9300 Photometer - Manual (Page 90)

Reagents and Equipment
YSI Phosphate No 1 LR Tablets
YSI Phosphate No 2 LR Tablets
YSI 9300 or 9500 Photometer
Round Test Tubes, 10 ml glass (PT 595)
Test Procedure
1 Fill test tube with sample to the 10 ml mark.
2 Add one Phosphate No 1 LR tablet, crush and mix to dissolve.
3 Add one Phosphate No 2 LR tablet, crush and mix to dissolve.
4 Stand for 10 minutes to allow full color development.
5 Select Phot 28 on photometer for result as mg/l PO
4
, or Phot 70 for result as
mg/l P.
6 Take photometer reading in usual manner (see photometer instructions).
Note
Phosphate concentrations can be expressed in a number of different ways. The
following factors may be used for the conversion of readings :-
To convert from PO
4
to P
2
O
5
- multiply by 0.75
To convert from PO
4
to P - multiply by 0.33
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