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Norm
ÖNORM EN 25813
Issue date: 1993 06 01
Water quality - Determination of dissolved oxygen - Iodometric method (ISO 5813:1983)
This International Standard specifies an iodometric method for
the determination of dissolved oxygen in water by the so-called
"Winkler procedure" modified in order to ...
Valid
Publisher:
Austrian Standards International
Format:
Digital | 8 Pages
Language:
German
| English
| Download GER/ENG
Optionally co-design standards:
ICS
This International Standard specifies an iodometric method for
the determination of dissolved oxygen in water by the so-called
"Winkler procedure" modified in order to make allowance for
certain interferences.
The iodometric method is the reference method for the determination
of dissolved oxygen in water. It is applicable to all
types of water having dissolved oxygen concentrations greater
than 0,2 rng/l, up to double saturation of oxygen (approximately
20 mg/l), which are free from interfering substances.
Readily oxidizable organic substances such as tannins, humic
acid and lignins, interfere. Oxidizable sulphur compounds such
as sulphides and thiourea also interfere, as do actively respiring
Systems which readily consume oxygen. In the presence of
such substances, it is preferable to use the electrochemical
probe method specified in ISO 5814.
Nitrites up to a concentration of 15 mg/l do not interfere with
the determination because they are destroyed by the addition
of sodium axide.
If oxidizing or reducing substances are present, it is necessary
to make modifications to the method; these are described in
clause 9.
If suspended matter, capable of fixing or consuming iodine, is
present, the method may be used with the modification
described in the annex, but it is preferable to use the electrochemical
probe method.
ÖNORM EN 25813
1993 06 01
Water quality - Determination of dissolved oxygen - Iodometric method (ISO 5813:1983)
Norm
↖
Norm
Issue date :
1990 03 29
Water quality — Determination of dissolved oxygen — Electrochemical probe method
Norm
Issue date :
1983 09 01
Water quality — Determination of dissolved oxygen — Iodometric method