Hach-Lange DR 5000 drinking water analysis, supplementary software LZV571 - Manual (Page 12)

12
Working procedures
2.3 Colour/Organic loading (SAC)
Principle
The parameters "colour” and "organic loading” can be determined
from a sample by measuring the intrinsic absorbance, that is
without using reagents. The spectral absorbance coefficients are
determined in m
-1 (Colour/SAC method) or in units based on a
PtCo standard (Colour (PtCo)/SAC method).
The colour of most yellow-brown natural waters and the outflows of
municipal sewage treatment plants can usually be measured at
436 nm. The colour of yellow-brown water can be measured by
comparison with suitable PtCo standards.
Range of application
Drinking water, surface water, wastewater
Measuring range
0–20
Accessories
• Spectrophotometer (254 nm and 436 nm)
• 50 mm rectangular cuvette (QS)
Interferences
Undissolved substances (turbidities) may cause high-bias results to
be obtained for the colour. This interference can be eliminated by
membrane filtration (pore size 0.45 µm).
Literature
DIN 38404 Part 1 (C1)
DIN 38404 Part 3 (C3)
2.3.1 Procedure Colour/Organic loading (SAC )
1. Select Stored Programs in the "Main Menu". Select test
number 903 and the required method (903 Colour/SAC or
903 Colour (PtCo)/SAC).
1. Insert the zero cuvette (distilled water) in the cell compartment.
Close the cell compartment. Touch Zero.
1. Insert the sample cuvette containing the first sample in the cell
compartment and close the cell compartment. Touch Read.
The result is displayed.