YSI 9300 Photometer - Manual (Page 29)

PHOTOMETER TEST INSTRUCTIONS
_________________________________________________________________________________________
Natural and treated waters may contain a variety of dissolved alkaline
substances such as carbonates, bicarbonates, hydroxides and, to a
lesser
extent, borates, phosphates and silicates. In water at neutral pH the alkalinity
derives mainly from the presence of bicarbonates.
Total alkalinity is an important test in determining the aggressiveness or scale
forming tendency of the water. If the total alkalinity is low the water may be
aggressive and cause corrosion to pipe work and structures; if the total
alkalinity is high the water may more readily promote scale formation. Alkalinity
control is therefore an important part of many water treatment programmes.
The YSI Alkaphot test uses a colorimetric method and covers the total alkalinity
range 0 - 500 mg/l CaCO
3
. The test is particularly suitable for checking natural
and drinking waters, swimming pool water, boiler water, etc.
Method
The YSI Alkaphot test is based on a unique colorimetric method and uses a
single tablet reagent. The test is simply carried out by adding a tablet to a
sample of the water. Under the conditions of the test, a distinctive range of
colors from yellow, through green, to blue is produced over the alkalinity range
0 - 500 mg/l CaCO
3
. The color produced in the test is indicative of the alkalinity
of the water and is measured using a YSI Photometer.
Reagents and Equipment
YSI Alkaphot 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.2.AUTO