Ozone, 0.02 - 1 Mg/L O - Grundfos DIT-L Bedienungsanleitung

7.5.2 Measurements
1. Fill a clean vial (∅24) with 10 ml of the water
0.0.0
sample and perform zero setting. See
section 6.2 Zero
2. Remove the vial from the sample chamber
and empty it, leaving a few drops in the vial.
3. Add one DPD No. 1 tablet (No 95727747)
straight from the foil and crush the tablet
using a clean stirring rod.
4. Fill a second clean vial with 10 ml of the
water.
5. Add one Glycine tablet (No 95727752)
straight from the foil and crush the tablet
using a clean stirring rod.
6. Close the vial tightly with the cap and swirl
gently several times until the tablet is
dissolved.
7. Transfer the contents of the second vial into
the prepared vial.
8. Close the vial tightly with the cap and swirl
gently several times until the tablets are
dissolved.
9. Place the vial in the sample chamber
correctly. See fig. 3.
10. Press the [Zero/Test] key.
Zero/Test
The method symbol flashes for
CL 6
approx. 3 seconds.
Write down the result as: reading G
RESULT
11. Remove the vial from the sample chamber,
empty the vial, rinse vial and cap several
times. Fill with a few drops of the water
sample.
12. Add one DPD No. 1 tablet (No 95727747)
straight from the foil and crush the tablet
using a clean stirring rod.
13. Add water sample to the 10 ml mark.
14. Close the vial tightly with the cap and swirl
gently several times until the tablet is
dissolved.
15. Place the vial correctly in the sample
chamber. See fig. 3.
Zero/Test
16. Press the [Zero/Test] key.
CL 6
The method symbol flashes for
approx. 3 seconds.
RESULT
Write down the result as: reading A
17. Remove the vial from the sample chamber.
18. Add one DPD No. 3 tablet (No 95727750)
straight from the foil to the same water
sample and crush the tablet using a clean
stirring rod.
19. Close the vial tightly with the cap and swirl
gently several times until the tablet is
dissolved.
20. Place the vial in the sample chamber
correctly. See fig. 3.
21. Wait for a reaction period of 2 minutes.
Zero/Test
22. Press the [Zero/Test] key.
CL 6
The method symbol flashes for
approx. 3 seconds.
RESULT
Write down the result as: reading C
23. Remove the vial from the sample chamber.
24. Add one DPD Acidifying tablet
(No 98032751) straight from the foil to the
same water sample and crush the tablet
using a clean stirring rod.
12
setting.
25. Close the vial tightly with the cap and swirl
gently several times until the tablet is
dissolved.
26. Wait for a reaction period of 2 minutes.
27. Add one DPD Neutralising tablet
(No 98032752) straight from the foil to the
same water sample and crush the tablet
using a clean stirring rod.
28. Close the vial tightly with the cap and swirl
gently several times until the tablet is
dissolved.
29. Place the vial in the sample chamber
correctly. See fig. 3.
30. Press the [Zero/Test] key.
Zero/Test
The method symbol flashes for
CL 6
approx. 3 seconds.
RESULT
Write down the result as: reading D
31. Calculate parameters,
see section
7.5.3 Calculation
The effective quantities of the desired parameters can be
calculated from the measured readings as follows:
Parameter
Chlorine dioxide
Chlorite
Free chloride
Combined chloride

7.6 Ozone, 0.02 - 1 mg/l O

Start the photometer and select method.
See section 6.1 Start.
7.6.1 Important notes
• Vial cleaning:
As many household cleaners (e.g. dishwasher detergent)
contain reducing substances, the subsequent determination of
ozone may show lower results. To avoid any measurement
errors, only use glassware free of chlorine demand.
Preparation: Put all applicable glassware into sodium
hypochlorite solution (0.1 g/l) for one hour, then rinse all
glassware thoroughly with deionised water.
• When preparing the sample, the escape of ozone gases,
e.g. by pipetting or shaking, must be avoided. The analysis
must take place immediately after taking the sample.
• The DPD colour development is carried out at a pH value of
6.2 to 6.5. The reagent tablet therefore contains a buffer for
the pH adjustment.
Strong alkaline or acidic water samples must be adjusted
between pH 6 and pH 7 before the tablet is added
(use 0.5 mol/l sulphuric acid and 1 mol/l sodium hydroxide,
respectively).
• For concentrations between 1.0 and 6 mg/l, the photometer
shows that the measuring range is exceeded [Hi].
Concentrations above 6 mg/l ozone can lead to results
showing 0 mg/l. In this event, the water sample must be
diluted with water free of ozone. 10 ml of the diluted sample
should be mixed with the reagent and the measurement
repeated (plausibility test)
• All oxidising agents in the samples interfere as they react in
the same way as ozone.
7.5.3 Calculation.
Formula
5 G
D - (C + 4 G)
A - G
C - A
O3
3