YSI 9300 Photometer - Manual (Page 137)

Test Procedure
1 Fill the test tube with sample to the 10 ml mark.
2 Add one Silica No 1 tablet, crush and mix to dissolve.
3 Add one Silica No 2 tablet, crush and mix to dissolve. Stand for 10 minutes
to allow full color development.
4 Add one Silica PR tablet, crush and mix to dissolve. Stand for two minutes.
(This stage may be omitted if the sample is known to be completely free of
phosphate and chlorine).
5 Select Phot 56 on photometer.
6 Take photometer reading in usual manner (see photometer instructions).
7 The result is displayed as mg/l SiO
2
.
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