1、August 2012DEUTSCHE NORM English price group 7No 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).ICS 71.040.40!%6s“2581980
2、www.din.deDIN 19267pH measurement Technical buffer solutions, preferably for the calibration of technical measuring installations,English translation of DIN 19267:2012-08pHMessung Technische Pufferlsungen, vorzugsweise zur Kalibrierung und Justierung von technischen pHMesseinrichtungen,Englische ber
3、setzung von DIN 19267:2012-08Mesure du pH Solutions tampons techniques, de prfrence pour ltalonnage des installations techniques de mesure du pH,Traduction anglaise de DIN 19267:2012-08SupersedesDIN 19267:197808www.beuth.deDocument comprises 10 pagesDDIN-Normenausschuss Materialprfung (NMP)DIN-Sprac
4、hendienst12.16DIN 19267:2012-08 2 A comma is used as the decimal marker. Contents Page Foreword . 3 1 Scope 4 2 Normative references 4 3 Terms and definitions 4 4 pH values and buffer capacities of technical buffer solutions 4 Annex A (informative) Examples of several technical buffer solutions 8 Bi
5、bliography . 10 DIN 19267:2012-08 3 Foreword This document (DIN 19267:2012-08) has been prepared by DIN-Normenausschuss Materialprfung (DIN Standards Committee Materials Testing), Working Committee NA 062-09-21 AA pH-Messtechnik. Attention is drawn to the possibility that some of the elements of thi
6、s document may be the subject of patent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. Amendments This standard differs from DIN 19267:1978-08 as follows: a) the standard has been technically and editorially revised; b) terms and definitions have
7、been updated. Previous editions DIN 19267: 1978-06, 1978-08 DIN 19267:2012-08 4 1 Scope This standard specifies requirements for technical buffer solutions. These buffer solutions are preferably used for the calibration and adjustment of technical pH measuring equipment and of pH meters in company l
8、aboratories. Measuring methods are recommended by means of which pH values and buffer capacities of such buffer solutions can be determined on the basis of pH reference buffer solutions in accordance with DIN 19266. NOTE The informative Annex A gives examples of technical pH buffer solutions. 2 Norm
9、ative references The following documents, 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)
10、 applies. DIN 19260, pH measurement General terms and definitions DIN 19261, pH measurement Measuring methods with potentiometric cells Terms and definitions DIN 19266, pH measurement Reference buffer solutions for the calibration of pH measuring equipment DIN 19268:2007-05, pH measurement pH measur
11、ement of aqueous solutions with pH measuring chains*)with pH glass electrodes and evaluation of measurement uncertainty 3 Terms and definitions For the purposes of this document, the terms and definitions given in DIN 19260 and DIN 19261 apply. 4 pH values and buffer capacities of technical buffer s
12、olutions 4.1 General The reference buffer solutions given in DIN 19266 form the basis for practical pH measurement. The pH values of these reference buffer solutions are traceable to primary standards, the pH values of which have been determined by the PTB, NIST and others by means of measurements u
13、sing primary methods 1. The accuracy and reproducibility have been confirmed by international round robin tests 2. The reference buffer solutions in accordance with DIN 19266 are diluted solutions (ionic strength 0,1 mol/kg). Consequently, they have a relative low buffer capacity. This complicates t
14、he handling in practice, since the pH value can change due to the addition of acid or bases (e.g. CO2from the air, carryovers from other solutions). For the calibration of pH combination electrodes in an industrial environment, further buffer solutions are therefore required, which have a higher buf
15、fer capacity. *)Translators note. A measuring chain within the meaning of this standard is generally referred to as a “combination electrode”. DIN 19267:2012-08 5 The pH values of these technical buffer solutions shall be measured in accordance with DIN 19268, in order to ensure the traceability of
16、the pH values to the reference buffer solutions in accordance with DIN 19266. The uncertainty budget illustrated in DIN 19268 shall be considered as a simplified illustration without consideration of influences during application. The temperature and the diffusion potentials on the diaphragm are sig
17、nificant influences 3, 4. Technical buffer solutions, as compared to reference buffer solutions, have higher ionic strength and, as a result, a higher buffer capacity. The pH values of technical buffer solutions are measured on the basis of reference buffer solutions in accordance with DIN 19266 and
18、 have measurement uncertainties due to this measurement. pH values of technical buffer solutions with pH 7, CO2-free, fully desalinated water shall be used. DIN 19267:2012-08 9 Table A.2 pH values of the technical buffer solutions given in Table A.1 as a function of temperature Temperature 0,1 moll-
19、1HCl Glycinea Acetateb Citric acid-Phosphate Boric acid-NaOH 0,1 moll-1NaOH C 0 1,08 - 4,67 6,89 9,48 - 10 1,09 3,10 4,66 6,84 9,37 13,37 20 1,09 3,07 4,65 6,80 9,27 12,96 25 1,09 3,06 4,65 6,79 9,23 12,75 30 1,10 3,05 4,65 6,78 9,18 12,61 40 1,10 3,04 4,66 6,76 9,09 12,29 50 1,11 3,04 4,68 6,76 9,0
20、0 11,98 60 1,11 3,04 4,70 6,76 8,92 11,69 70 1,11 3,04 4,72 6,76 8,88 11,43 80 1,12 3,05 4,75 6,78 8,85 11,19 90 1,13 3,07 4,79 6,80 8,82 10,99 aValues according to measurements by F. G. K. Baucke, R. Naumann and O. Petersen. bIn accordance with 6. Table A.3 Confidence intervals of the pH values giv
21、en in Tables A.1 and A.2 with a statistical certainty of 95 % Buffer solution Confidence interval (statistical certainty 95 %) at 25 C at 60 C 0,1 moll-1HCl null 0,024 null 0,021 Glycine null 0,017 null 0,015 Acetate null 0,011 null 0,010 Citric acid-Phosphate null 0,014 null 0,016 Boric acid-NaOH n
22、ull 0,019 null 0,018 0,1 moll-1NaOH null 0,014 null 0,033 The data given in Table A.3 have been determined on separately prepared technical buffer solutions during a round robin test in which the following laboratories participated: F.G.K. Baucke, Jenaer Glaswerk Schott U. Fritze, Bayer AG, Leverkus
23、en; H. Galster, Ingold KG, Frankfurt and O. Petersen, Bayer AG, Uerdingen. DIN 19267:2012-08 10 Bibliography 1 IUPAC Recommendation 2002, Pure Appl. Chem. 74, 2169 (2002) 2 P. de Bievre, R. Dypkaer, A. Faigl, D. B. Hibbert: Metrological Traceability of Measurement Results in Chemistry, Concepts and
24、Implementation, Provisional IUPAC recommendation (2009) 3 G. Tauber, Industrielle pH-Messung Beitrge der Temperatur zur Messunsicherheit (Industrial pH measurement Contribution of temperature to measurement uncertainty), tm Technisches Messen, 77, 3 (2010) 4 G. Tauber, Industrielle pH-Messung Beitrg
25、e der Diffusionspotenziale zur Messunsicherheit (Industrial pH measurement Contribution of diffusion potentials to measurement uncertainty), tm Technisches Messen 76, 6 (2009) 5 O. Petersen, Technische Pufferlsungen als Eichlsungen fr pH-Messungen im Temperaturbereich zwischen 0 und 100 C (Technical
26、 buffer solutions as calibration solutions for pH measurement at temperatures from 0 C to 100 C ), Chem. Ing. Techn., 40 (1968), pp. 76-79 6 R. Naumann and Ch. Alexander, Zum pH-Wert des Acetat-Puffers 0,1N Essigsure, 0,1N Natriumacetat (On the pH value of an acetate buffer 0,1N acetic acid, 0,1N sodium acetate), Chem. Ing. Techn., 49 (1977), pp. 339-340
