1、February 2013 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).I
2、CS 13.060.50!$F“1943597www.din.deDDIN EN ISO 5814Water quality Determination of dissolved oxygen Electrochemical probe method (ISO 5814:2012);English version EN ISO 5814:2012,English translation of DIN EN ISO 5814:2013-02Wasserbeschaffenheit Bestimmung des gelsten Sauerstoffs Elektrochemisches Verfa
3、hren (ISO 5814:2012);Englische Fassung EN ISO 5814:2012,Englische bersetzung von DIN EN ISO 5814:2013-02Qualit de leau Dosage de loxygne dissous Mthode lectrochimique la sonde (ISO 5814:2012);Version anglaise EN ISO 5814:2012,Traduction anglaise de DIN EN ISO 5814:2013-02SupersedesDIN EN 25814:1992-
4、11www.beuth.deDocument comprises 21 pagesIn case of doubt, the German-language original shall be considered authoritative.01.13 DIN EN ISO 5814:2013-02 2 A comma is used as the decimal marker. National foreword This document (EN ISO 5814:2012) has been prepared by Technical Committee ISO/TC 147 “Wat
5、er quality” in collaboration with Technical Committee CEN/TC 230 “Water analysis” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Wasserwesen (Water Practice Standards Committee), Working Committee NA 119-01-03-01-21 AK Gelstsauerstoffmess
6、ung of NA 119-01-03 AA Wasseruntersuchung. This standard is part of the series Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlamm-untersuchung Gasfrmige Bestandteile (Gruppe G) (German standard methods for the examination of water, waste water and sludge Gaseous constituents (group D) and
7、 describes method G 22. Designation of method G 22 “Determination of dissolved oxygen - Electrochemical probe method”: Method DIN EN ISO 5814 G 22 The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 3696 DIN ISO 3696 ISO 5813 DIN EN 25813 I
8、SO 7888 DIN EN 27888 Expert assistance and specialized laboratories will be required to perform the analyses described in this standard. Existing safety requirements are to be observed. Depending on the objective of the analysis, a check shall be made on a case-by-case basis as to whether and to wha
9、t extent additional conditions will have to be specified. German standard methods for the examination of water, waste water and sludge Standard methods published as DIN Standards are obtainable from Beuth Verlag GmbH, either individually or grouped in volumes. The standard methods included in the lo
10、ose-leaf publication entitled Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung will continue to be published by Wiley-VCH Verlag GmbH b) Clause 4 “Interferences” has been included; c) the list of reagents has been extended; d) requirements for the sampling of water samples h
11、ave been specified (see 7.1); e) calibration in water vapour-saturated air has been given in more detail (see 7.3.3); f) calibration in air-saturated water has been deleted; g) further tables have been added to Annex A “Physicochemical data for oxygen in water”; h) Annex B “Performance data” has bee
12、n included; i) the standard has been editorially revised. Previous editions DIN 38408-22: 1986-11 DIN EN 25814: 1992-11 DIN EN ISO 5814:2013-02 4 National Annex NA (informative) Bibliography DIN EN 25813, Water quality Determination of dissolved oxygen Iodometric method DIN EN 27888, Water quality D
13、etermination of electrical conductivity DIN ISO 3696, Water for analytical laboratory use Specification and test methods EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 5814 October 2012 ICS 13.060.50 Supersedes EN 25814:1992 English Version Water quality Determination of dissolved oxygen E
14、lectrochemical probe method (ISO 5814:2012) Qualit de leau Dosage de loxygne dissous Mthode lectrochimique la sonde (ISO 5814:2012) Wasserbeschaffenheit Bestimmung des gelsten Sauerstoffs Elektrochemisches Verfahren (ISO 5814:2012) This European Standard was approved by CEN on 4 August 2012. CEN mem
15、bers are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on applicat
16、ion to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Manage
17、ment Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
18、 Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 B
19、russels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 5814:2012: E Contents PageForeword iv1 Scope 12 Normative references . 13 Principle . 14 Interferences . 25 Reagents 26 Apparatus 27 Sampling and analysis procedure 3
20、7.1 Sampling 37.2 Measuring technique and precautions to be taken 37.3 Calibration . 47.4 Determination . 48 Calculation and expression of results . 58.1 Dissolved oxygen concentration 58.2 Dissolved oxygen expressed as percentage saturation . 59 Test report . 5Annex A (informative) Physicochemical
21、data for oxygen in water 6Annex B (informative) Performance data .12Bibliography .14DIN EN ISO 5814:2013-02 EN ISO 5814:2012 (E) 23 Foreword This document (EN ISO 5814:2012) has been prepared by Technical Committee ISO/TC 147 “Water quality” in collaboration with Technical Committee CEN/TC 230 “Wate
22、r analysis” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2013, and conflicting national standards shall be withdrawn at the latest by April 2013.
23、Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 25814:1992. According to the CEN/CENELEC Internal Regulati
24、ons, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy
25、, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 5814:2012 has been approved by CEN as a EN ISO 5814:2012 without any modification. DIN EN ISO 5814
26、:2013-02 EN ISO 5814:2012 (E) 3WARNING Persons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate sa
27、fety and health practices and to ensure compliance with any national regulatory conditions.IMPORTANT It is absolutely essential that tests conducted according to this International Standard be carried out by suitably trained staff.1 ScopeThis International Standard specifies an electrochemical metho
28、d for the determination of dissolved oxygen in water by means of an electrochemical cell which is isolated from the sample by a gas permeable membrane.Measurement can be made either as a concentration of oxygen in milligrams per litre, percentage saturation (% dissolved oxygen) or both. The method m
29、easures oxygen in water corresponding to 1 % to 100 % saturation. However, most instruments permit measurement of values higher than 100 %, i.e. supersaturation.NOTE Supersaturation is possible when the partial pressure of oxygen is higher than in air. Especially when strong algal growth is present,
30、 supersaturation of up to 200 % and above can occur.The method measures oxygen in water with a saturation higher than 100 %, when special arrangements to prevent the outgassing of oxygen during the handling and measurement of the sample are made.The method is suitable for measurements made in the fi
31、eld and for continuous monitoring of dissolved oxygen, as well as measurements made in the laboratory. It is the preferred method for highly coloured and turbid waters, and also for analysis of waters not suitable for the Winkler titration method because of iron- and iodine-fixing substances, which
32、can interfere in the iodometric method specified in ISO 58131.The method is suitable for drinking waters, natural waters, waste waters, and saline waters. If used for saline waters, such as sea or estuarine waters, a correction for salinity is essential.2 Normative referencesThe following documents,
33、 in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3696, Water for analytical l
34、aboratory use Specification and test methods3 PrincipleImmersion of a probe, consisting of a cell enclosed by a selective membrane and containing the electrolyte and at least two metallic electrodes, in the water to be analysed.NOTE The membrane is effectively impermeable to water and ionic dissolve
35、d matter, but is permeable to oxygen and a certain number of other gases.One of the electrodes is made of a noble metal like gold or platinum. Oxygen is reduced at its surface by an electrochemical process. In order to make this process possible, a suitable electrochemical potential is established a
36、t this electrode. For polarographic probes, this is achieved by applying an external voltage related to a second electrode. Galvanic probes are able to build up the potential by themselves.DIN EN ISO 5814:2013-02 EN ISO 5814:2012 (E) 4The current resulting from the reduction of oxygen is directly pr
37、oportional to the rate of transport of oxygen through the membrane and the layer of electrolyte, and hence to the partial pressure of the oxygen in the sample at a given temperature.Temperature has two different influences. The first relates to the variation of gas permeability of the membrane with
38、temperature. So the primary signal of the probe has to be compensated with a built-in temperature sensor. Meters manufactured recently are able to do this automatically. The second is the temperature effect on the electrode reactions.To calculate the percentage of saturation of samples in contact wi
39、th an atmosphere, it is necessary to include the effective pressure. This can be performed manually or by implementing a pressure sensor for automatic compensation. Salinity can also be an influence.4 InterferencesGases and vapors such as chlorine, hydrogen sulfide, amines, ammonia, bromine, and iod
40、ine which diffuse through the membrane can interfere, if present, by affecting the measured current.Other substances present in the sample can interfere with the measured current by causing obstruction, deterioration of the membrane or corrosion of the electrodes. These include solvents, oils, sulfi
41、des, carbonates, and biofilms.5 ReagentsDuring analysis, use only reagents of recognized analytical grade.5.1 Water, grade 2, as specified in ISO 3696, optionally from commercial sources.5.2 Sodium sulfite, anhydrous, Na2SO3or heptahydrate, Na2SO37H2O.5.3 Cobalt(II) salt, for example cobalt(II) chlo
42、ride hexahydrate, CoCl26H2O.5.4 Nitrogen gas, N2, purity 99,995 % volume fraction or better.6 Apparatus6.1 Measuring instrument, comprising the components specified in 6.1.1 and 6.1.2.6.1.1 Measuring probe, either of the galvanic type (e.g. lead/silver) or the polarographic type (e.g. silver/gold) w
43、ith, if required, a temperature-sensitive compensating device.6.1.2 Meter, graduated to show the concentrations of dissolved oxygen directly, and/or percentage saturation with oxygen.6.2 Thermometer, graduated in at least 0,5 C divisions.NOTE Commonly a temperature sensor is integrated into the inst
44、rument (6.1).6.3 Barometer, graduated to 1 hPa.NOTE Usually the barometer is integrated into the instrument (6.1).DIN EN ISO 5814:2013-02 EN ISO 5814:2012 (E) 57 Sampling and analysis procedure7.1 Sampling7.1.1 GeneralSamples should always be handled so that transfer of oxygen between water sample a
45、nd air is inhibited.As a matter of principle, the oxygen concentration shall be measured directly on site in the water body to be analysed.If direct measurement in the water body is not possible, the measurement can also be taken in a gas-tight connected flow-through device or immediately after samp
46、ling as a discrete sample.Any discrete sampling procedure results in a higher measurement uncertainty.While filling the sample vessel during sampling, oxygen uptake or oxygen stripping shall be minimized. Sample transfer shall occur without any turbulence, i.e. by maintaining a laminar flow.7.1.2 Di
47、p-sampling (e.g. surface waters)Take the sample by carefully and slowly dipping the sample vessel.7.1.3 Sampling from tapsConnect an inert sampling tube, in a gas-tight fashion, to the tap and insert the sampling tube all the way down to the bottom of the sampling vessel. Ensure that the volume of w
48、ater allowed to overflow is at least three times the capacity of the vessel.7.1.4 Sampling with pumpsOnly water-displacing submersible pumps should be used. Pumps that function according to the principle of air displacement are not suitable. Fill the sample vessel from the bottom, using a sampling tube, and allow the water to overflow. During sample transfer, the volume flow rate shall be controlled in order to guarantee a mainly laminar flow. Ensure that the volume of water allowed to overfl
