YSI 9300 Photometer - Manual (Page 65)

PHOTOMETER TEST INSTRUCTIONS
__________________________________________________________________________________________
Water hardness is caused by the presence of calcium and magnesium salts.
High levels of hardness prevent the formation of lather with soap, and can
cause scaling in water systems - particularly boilers, heat exchangers and steam
generating plant. Hardness is an important control test in a wide variety of
applications.
The YSI Hardness test provides a simple method of checking water hardness over
the range 0 - 500 mg/l CaCO
3
.
Method
The YSI Hardicol test is based on a unique colorimetric method. The reagents
are provided in tablet form and the test is carried out simply by adding the
appropriate tablets to a sample of the water.
Under the controlled conditions of the test calcium and magnesium ions react
with Hardicol indicator to produce a purple coloration. The intensity of the color
is proportional to the total hardness of the water and is measured using a YSI
Photometer.
Reagents and Equipment
YSI Hardicol No 1 Tablets
YSI Hardicol No 2 Tablets
YSI 9300 or 9500 Photometer
Round Test Tubes, 10 ml glass (PT 595)
Photometer Method
AUTOMATIC
WAVELENGTH
SELECTION
0 – 500 mg/l CaCO
3
PHOT.15.AUTO