1、BS EN ISO10523:2012ICS 13.060.50NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDWater quality Determination of pHNational forewordThis British Standard is the UK implementation of EN ISO 10523:2012. It is identical to ISO 10523:2008. It supersedes BS ISO 10523:2
2、008 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee EH/3, Water quality, to Subcommittee EH/3/2, Physical chemical and biochemical methods.A list of organizations represented on this subcommittee can be obtained on request to its secretary.This publica
3、tion does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN ISO 10523:2012This British Standardwas published under theauthority of the StandardsPo
4、licy and StrategyCommittee on 30 June2010 The British Standards Institution 2012. Published by BSI Standards Limited 2012.Amendments/corrigenda issued since publicationDate Comments 30 April 2012 This corrigendum renumbers BS ISO 10523:2008 as BS EN ISO 10523:2012ISBN 978 0 580 75429 6EUROPEAN STAND
5、ARD NORME EUROPENNE EUROPISCHE NORM EN ISO 10523 February 2012 ICS 13.060.50 English Version Water quality - Determination of pH (ISO 10523:2008) Qualit de leau - Dtermination du pH (ISO 10523:2008) Wasserbeschaffenheit - Bestimmung des pH-Wertes (ISO 10523:2008) This European Standard was approved
6、by CEN on 15 January 2012. CEN members 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 sta
7、ndards may be obtained on application 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
8、notified to the CEN-CENELEC Management 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lith
9、uania, 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 Brusse
10、ls 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 10523:2012: Ei BS EN ISO 10523:2012 EN ISO 10523:2012 (E)PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file
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14、e reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. +
15、41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland iiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Interferences . 2 6 Reagents 3 7 Apparatus 3 8 Sampling 4 9 Procedure 5
16、 9.1 Preparation 5 9.2 Calibration and adjustment of the measuring equipment 5 9.3 Measurement of the samples 6 10 Expression of results . 6 11 Test report . 6 Annex A (informative) pH values of primary standard reference solutions. 7 Annex B (informative) Operative measurements in flow systems 8 An
17、nex C (informative) Field measurement (on-site measurement) 10 Annex D (informative) Measurements of the pH value in water with low ionic strength 11 Annex E (informative) Performance data. 12 Bibliography . 13 ISO 2012BS EN ISO 10523:2012 EN ISO 10523:2012 (E)iii Foreword The text of ISO 10523:2008
18、 has been prepared by Technical Committee ISO/TC 147 “Water quality” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 10523:2012 by Technical Committee CEN/TC 230 “Water analysis” the secretariat of which is held by DIN. This European Standard shall be gi
19、ven the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2012, and conflicting national standards shall be withdrawn at the latest by August 2012. Attention is drawn to the possibility that some of the elements of this document may
20、be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria,
21、Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdo
22、m. Endorsement notice The text of ISO 10523:2008 has been approved by CEN as a EN ISO 10523:2012 without any modification. ISO 2012BS EN ISO 10523:2012 EN ISO 10523:2012 (E)Introduction The measurement of the pH value of water is of great importance for many types of sample. High and low pH values a
23、re toxic for aquatic organisms, either directly or indirectly. The pH value is the most useful parameter in assessing the corrosive properties of an aquatic environment. Also, it is important for the effective operation of water treatment processes and their control (e.g. flocculation and chlorine d
24、isinfection), control of plumbosolvency of drinking waters and biological treatment of sewage and sewage discharges. The electrometric methods addressed in this International Standard are based on measuring the potential difference of an electrochemical cell where one of the two half-cells is a meas
25、uring electrode and the other is a reference electrode. The potential of the measuring electrode is a function of the hydrogen ion activity of the measuring solution (Reference 5). In view of its great practical importance, universality and exactitude, only measuring using the pH glass electrode is
26、described in this International Standard. In the reference electrode, electrolytes applied can be in liquid, polymer or gel form. ISO 2012BS EN ISO 10523:2012 EN ISO 10523:2012 (E)ivThis page deliberately set blankINTERNATIONAL STANDARD1Water quality Determination of pH WARNING Persons using this In
27、ternational Standard should be familiar with normal laboratory practice. This International Standard does not purport to address any safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any na
28、tional regulatory conditions. IMPORTANT It is absolutely essential that tests conducted according to this International Standard be carried out by suitably trained staff. 1 Scope This International Standard specifies a method for determining the pH value in rain, drinking and mineral waters, bathing
29、 waters, surface and ground waters, as well as municipal and industrial waste waters, and liquid sludge, within the range pH 2 to pH 12 with an ionic strength below I = 0,3 mol/kg (conductivity: 25 C1012. Moreover, it shall be possible to change the display of the pH meter to give readings of either
30、 the pH value or the voltage. BS EN ISO 10523:2012 EN ISO 10523:2012 (E) ISO 2012 4 The resolution of the pH value reading on the pH meter shall be 0,01 or better. Whether the pH meter is provided with a manual or an automatic routine calibration is not a limiting characteristic within the scope of
31、this International Standard. NOTE The temperature compensation carried out by commercially available pH meters is based on the Nernst equation; i.e. it is dependent on temperature, and the corresponding theoretical slope of the electrodes is taken into account in the indication of the pH value. This
32、 does not, however, compensate for the temperature dependence on the pH value of the measuring solution. 7.4 Glass electrode and reference electrode. The chain zero-point of glass electrodes should not deviate by more than pH = 0,5 (manufacturers declared value) from the nominal pH electrode value.
33、The value of the practical slope shall be at least 95 % of the theoretical slope. Use electrodes with electrolyte solutions and a flow rate of 0,1 ml/day to 2 ml/day as reference electrodes. For reference electrodes with an electrolyte solution, ensure that an excess hydrostatic pressure is generate
34、d by setting the filling level of the electrolyte in the reference electrode to be higher than that of the buffer solution or the measuring solution, as appropriate. It is also possible to use pressurized reference electrodes. In limited applications, reference electrodes with a solidified electroly
35、te (electrolyte gel or a polymerizate of an electrolyte) may also be used. Store the electrodes according to the manufacturers instructions. For samples with low conductivity, electrodes with high electrolyte discharge should be used. If the conductivity is 30 mS/m, it is also possible to use an ele
36、ctrolyte gel or polymerizate in the reference electrodes. In general, ensure that for electrolyte gels or polymerizates, the exchange within the diaphragm is not be caused by the discharge of the electrolyte, but by diffusion of the ions involved. 7.5 Stirrer or agitator, operating with a minimum ex
37、change of gas between the test portion and air. 8 Sampling The pH value may change rapidly as a result of chemical, physical or biological processes in the water sample. For this reason, whenever applicable, it is advisable to measure the pH value immediately at the sampling point. If this is not po
38、ssible, take a water sample in a sampling bottle (7.1). When filling the sampling bottle, avoid gas exchange, e.g. release of carbon dioxide, between the sample and the ambient air. Fill the bottle completely and stopper it, bubble-free, e.g. with a solid stopper. Samples should be kept cool (2 C to
39、 8 C) and in the dark during transport and storage (ISO 5667-3). The sampling bottle is preferably filled by flushing to overflowing from a water sampler via a flexible tube extending to the bottom of the bottle. In the laboratory, measure the pH value as soon as possible. When the samples are measu
40、red in the laboratory, check possible influences of transport and storage on the pH value of the samples to be analysed. Pay special attention to sampling strategies for certain types of water matrices (see ISO 5667-3). Usually, sampling and transport are the major factors of uncertainty when measur
41、ing the pH value in the laboratory. Therefore, the results of on-site measurements often show lower measurement uncertainty. BS EN ISO 10523:2012 EN ISO 10523:2012 (E) ISO 2012 59 Procedure 9.1 Preparation Follow the manufacturers instructions when operating the pH electrode. Ensure the functionalit
42、y of the pH electrode by periodic maintenance and testing (9.2). Prepare the calibration buffer solutions. For devices with automatic buffer identification, follow the manufacturers calibration instructions. Choose the buffer solutions so that the expected measurement of the sample lies between the
43、values of the two buffers. When using a pH electrode without an internal temperature sensor, immerse a temperature sensor in the test solution. For measurement, prepare the glass and either the reference electrode or the mono-rod pH electrode, following the manufacturers instructions. Turn on the me
44、asuring device; for devices with automatic buffer identification, activate the stored data of the buffer solutions prepared for calibration. Measure the temperature of the buffer and of the sample solutions. If possible, buffer and sample should have the same temperature. If there is no temperature
45、sensor, adjust the device to the measuring temperature. Take the pH values of the buffer solutions from the respective certificates, depending on the existing temperature (for examples of buffers, see Annex A) or use automatic buffer recognition. 9.2 Calibration and adjustment of the measuring equip
46、ment Calibrate the pH electrode at two points using buffer solutions of the expected range of pH values (two-point calibration), following the manufacturers instructions. Afterwards, adjust the devices manually, based on the data determined. For automatic measuring devices, ensure that the prepared
47、buffer solutions correspond to the data of the buffer solutions stored in the software of the measuring device. Immerse the pH electrode and the temperature sensor in the first buffer, usually the one at pH 7, which is used for adjusting the zero point. Subsequently stir to avoid the enrichment of p
48、otassium chloride caused by leaking reference electrolytes near the glass electrode. Turn off the stirrer and start the calibration procedure on the measuring device. Automatic devices independently identify the stability of the measurement, store this value and adjust the zero point. When using dev
49、ices with manual adjustment, initially adjust the zero point at pH 7, unless otherwise specified in the manufacturers instructions. Thoroughly rinse the pH electrode and the temperature sensor before, between, and after the measurements using water (6.1). Immerse the pH electrode in the second buffer solution and stir. Turn off the stirrer and start the calibration procedure for the se
