YSI 9300 Photometer - Manual (Page 117)

PHOTOMETER TEST INSTRUCTIONS
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The YSI Chloridol test provides a simple method for measuring chloride salt levels.
There are many applications in water technology that require determination of
chlorides. These include the measurement of low levels of chloride to determine the
extent of carry-over in boiler condensates; chloride determination to assess salt build-
up in swimming pools or boiler waters; and measurement of high chloride levels for
testing sea water or determining the saltiness of brackish waters. A further application
is for checking swimming pools where salt has been artificially added to simulate sea
water bathing, or where this is necessary for the operation of certain types of
electrolytic hypochlorite generator.
The test can be used for measuring these widely different chloride concentrations by
varying the sample size selected. The test ranges covered are 0 - 50 mg/l Cl, 0 - 500
mg/l Cl, 0 - 10,000 mg/l NaCl and 0 - 50,000 mg/l NaCl.
Method
The YSI Chloridol test is based on a tablet reagent system containing silver nitrate.
Chlorides react with the silver nitrate to produce insoluble silver chloride. At the
chloride levels encountered in the test, the insoluble silver chloride is observed as
turbidity in the test sample. The degree of turbidity is proportional to the chloride
concentration and is measured using a YSI Photometer.
The test is carried out under acidic and oxidising conditions so as to prevent interference
from complexing agents such as EDTA and polyphosphates, and from any reducing
substances which may be present in the water. Polyacrylates do however interfere and the
test should not be used on industrial waters using polyacrylate-based treatments.
The formation of the precipitate in the Chloridol test may be subject to matrix
effects in the presence of high total dissolved solids (TDS). The 0 – 50 mg/l Cl
range is calibrated only for use on softened waters and condensates, and should
not be used for other samples. The dilution step in the other ranges reduces the
TDS to acceptable levels and prevents this effect.
Photometer Method
AUTOMATIC
WAVELENGTH
SELECTION
0 – 50 mg/l Cl to
0 – 50,000 mg/l NaCl
PHOT.46.AUTO