1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 4787:2011Laboratory glassware Volumetric instruments Methods for testing of capacityand for use (ISO 4787:2010,Corrected version 2010-06-15)BS EN ISO 4787:2011 BRITISH
2、STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 4787:2011.It is identical to ISO 4787:2010. It supersedes BS EN ISO 4787:2010which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee LBI/36/1, Laboratory Glass and Plastics Appara
3、tus.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 72631 6ICS 17.060; 71.040.20Compliance
4、 with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2011.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO
5、4787 March 2011 ICS 17.060 Supersedes EN ISO 4787:2010English Version Laboratory glassware - Volumetric instruments - Methods for testing of capacity and for use (ISO 4787:2010, Corrected version 2010-06-15) Verrerie de laboratoire - Instruments volumtriques - Mthodes de vrification de la capacit et
6、 dutilisation (ISO 4787:2010, Version corrige 2010-06-15) Laborgerte aus Glas - Volumenmessgerte - Prfverfahren und Anwendung (ISO 4787:2010, korrigierte Fassung 2010-06-15) This European Standard was approved by CEN on 31 January 2011. CEN members are bound to comply with the CEN/CENELEC Internal R
7、egulations 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 application to the CEN-CENELEC Management Centre or to any CEN m
8、ember. 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 Management Centre has the same status as the official versions
9、. 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, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Sloven
10、ia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nat
11、ional Members. Ref. No. EN ISO 4787:2011: EEN ISO 4787:2011 (E) 3 Foreword The text of ISO 4787:2010, Corrected version 2010-06-15 has been prepared by Technical Committee ISO/TC 48 “Laboratory equipment” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 4
12、787:2011 by Technical Committee CEN/TC 332 “Laboratory equipment” 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 September 2011, and conflicting national
13、standards shall be withdrawn at the latest by September 2011. 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
14、 EN ISO 4787:2010. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungar
15、y, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 4787:2010, Corrected version 2010-06-15 has been approved by CEN as a EN ISO 478
16、7:2011 without any modification. ISO 4787:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv 1 Scope1 2 Normative references1 3 Terms and definitions .2 4 Summary of method2 5 Volume and reference temperature .2 5.1 Unit of volume2 5.2 Reference temperature .2 6 Apparatus and calibrat
17、ion liquid .2 7 Factors affecting the accuracy of volumetric instruments.3 7.1 General .3 7.2 Temperature.3 7.3 Cleanliness of glass surface 3 7.4 Quality of used volumetric instruments4 7.5 Delivery time and waiting time.4 8 Setting the meniscus 4 8.1 General .4 8.2 Meniscus of transparent liquids
18、4 8.3 Meniscus of opaque liquids .5 9 Calibration procedure .5 9.1 General .5 9.2 Test room .5 9.3 Filling and delivery6 9.4 Weighing.7 9.5 Evaluation.7 10 Use 7 10.1 General .7 10.2 Volumetric flasks (see ISO 1042) .8 10.3 Measuring cylinders (see ISO 4788) 8 10.4 Burettes (see ISO 385).8 10.5 Pipe
19、ttes.9 Annex A (informative) Cleaning of volumetric glassware 10 Annex B (normative) Calculation of volume 11 Bibliography21 ISO 4787:2010(E) iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO m
20、ember bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governm
21、ental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Dir
22、ectives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bo
23、dies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 4787 was prepared by Technical Committee ISO/TC 48, Laboratory equipment, Su
24、bcommittee SC 6, Laboratory and volumetric ware. This second edition cancels and replaces the first edition (ISO 4787:1984), which has been technically revised to incorporate the following changes: a) the potassium dichromate cleaning method in Annex A has been deleted; b) new tables for calculation
25、 of test results have been added to Annex B; c) the description of the test (calibration) methods has been modified to be more precise; d) test methods have been separated from recommendations for use. This corrected version of ISO 4787:2010 incorporates the following corrections: Figure 1 on page 5
26、 has been corrected to show the correct setting of the meniscus as described in the text; Figure 2 on page 5 has been improved to better illustrate what the user of the instrument really sees when setting the meniscus. INTERNATIONAL STANDARD ISO 4787:2010(E) ISO 2010 All rights reserved 1Laboratory
27、glassware Volumetric instruments Methods for testing of capacity and for use 1 Scope This International Standard provides methods for the testing, calibration and use of volumetric instruments made from glass in order to obtain the best accuracy in use. NOTE Testing is the process by which the confo
28、rmity of the individual volumetric instrument with the appropriate standard is determined, culminating in the determination of its error of measurement at one or more points. The International Standards for the individual volumetric instruments include clauses on the definition of capacity; these cl
29、auses describe the method of manipulation in sufficient detail to define the capacity without ambiguity. This International Standard contains supplementary information. The procedures are applicable to volumetric instruments with nominal capacities in the range of 0,1 ml to 10 000 ml. These include:
30、 single-volume pipettes (see ISO 648) without subdivisions; graduated measuring pipettes and dilution pipettes, with partial or complete subdivisions (see ISO 835); burettes (see ISO 385); volumetric flasks (see ISO 1042); and graduated measuring cylinders (see ISO 4788). The procedures are not reco
31、mmended for testing of volumetric instruments with capacities below 0,1 ml such as micro-glassware. This International Standard does not deal specifically with pyknometers as specified in ISO 3507. However, the procedures specified below for the determination of volume of glassware can, for the most
32、 part, also be followed for the calibration of pyknometers. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (i
33、ncluding any amendments) applies. ISO 385, Laboratory glassware Burettes ISO 648, Laboratory glassware Single-volume pipettes ISO 835, Laboratory glassware Graduated pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3696, Water for analytical laboratory use Specification and tes
34、t methods ISO 4788, Laboratory glassware Graduated measuring cylinders ISO/IEC Guide 99, International vocabulary of metrology Basic and general concepts and associated terms (VIM) ISO 4787:2010(E) 2 ISO 2010 All rights reserved3 Terms and definitions For the purposes of this document, the terms and
35、 definitions given in ISO/IEC Guide 99 apply. 4 Summary of method The general procedure is based upon a determination of volume of water, either contained in or delivered by the volumetric instrument. This volume of water is based upon knowledge of its mass under consideration of buoyancy and its ta
36、bulated density (gravimetric method). 5 Volume and reference temperature 5.1 Unit of volume The unit of volume shall be the millilitre (ml), which is equivalent to one cubic centimetre (cm3). 5.2 Reference temperature The standard reference temperature, i.e. the temperature at which the volumetric i
37、nstrument is intended to contain or deliver its volume (capacity), shall be 20 C. When the volumetric instrument is required for use in a country which has adopted a standard reference temperature of 27 C (the alternative recommended in ISO 384 for tropical use), this figure shall be substituted for
38、 20 C. 6 Apparatus and calibration liquid 6.1 Balance, with a resolution and standard deviation appropriate to the selected volume of the apparatus under test (see Table 1). The resolution of the display, the standard deviation and the linearity of the balance will be a limiting factor in the accura
39、cy of the measurements. The balance shall be calibrated with adequate accuracy (see 9.4). Table 1 Recommended balance Selected volume under testaV Resolutionmg Standard deviation(repeatability) mg Linearity mg 100 l 2 000 ml 0,1 1 10 100 0,2 1 10 100 0,2 2 20 200 aFor practical purposes, the nominal
40、 volume may be used to choose the balance. 6.2 Thermometer, to measure the temperature of the calibration liquid (water) with a measurement error of maximum 0,2 C for liquid volumes 1 000 ml and with a measurement error of maximum 0,1 C for liquid volumes W 1 000 ml. 6.3 Hygrometer, to measure the h
41、umidity in the test room with a measurement error of maximum 5 % within the humidity range of 35 % to 85 %. ISO 4787:2010(E) ISO 2010 All rights reserved 36.4 Barometer, to measure the atmospheric pressure in the test room with a measurement error of maximum 1 kPa. 6.5 Calibration liquid, distilled
42、or deionized water complying with ISO 3696, Grade 3 should be used for testing. 6.6 Receiving vessel, conical flask with ground joint, manufactured from glass, e.g. in accordance with ISO 4797. The nominal volume of the conical flask shall correspond to the volume of liquid to be measured. 7 Factors
43、 affecting the accuracy of volumetric instruments 7.1 General The same sources of error are, naturally, inherent both in calibration and use. In the former, every attempt is made to reduce these errors to a minimum; in the latter, the care needed is dependent upon the degree of accuracy required. Wh
44、en the greatest possible accuracy is desired, the volumetric instrument should be used as closely as possible to the manner in which it has been calibrated. 7.2 Temperature 7.2.1 Temperature of the volumetric instrument 7.2.1.1 The capacity of the volumetric instruments varies with change of tempera
45、ture. The particular temperature at which a volumetric instrument is intended to contain or deliver its nominal capacity is the “reference temperature” of the instrument (see 5.2). 7.2.1.2 A volumetric instrument which was adjusted at 20 C, but used at 27 C, would show an extra error of only 0,007 %
46、 if it is made of borosilicate glass having a coefficient of cubical thermal expansion of 9,9 106C1and of 0,02 % if it is made of soda-lime glass having a coefficient of cubical thermal expansion of 27 106C1. These errors are smaller than the limits of error for most volumetric instruments. It follo
47、ws, therefore, that the reference temperature is of minor importance in practical use. However, when performing calibrations, it is important to refer to the reference temperature. 7.2.2 Temperature of calibration liquid The temperature of the water used for the calibration shall be measured to 0,1
48、C. Corrections for differences in temperature from the reference temperature shall be applied in accordance with Annex B. 7.3 Cleanliness of glass surface The volume contained in, or delivered by, a volumetric instrument depends on the cleanliness of the internal glass surface. Lack of cleanliness r
49、esults in errors through a poorly shaped meniscus involving two defects: incomplete wetting of the glass surface, i.e. the liquid surface meets the glass at an arbitrary angle instead of forming a curve such that it meets the glass tangentially; a generally increased radius of curvature, due to contamination of the liquid surface reducing the surface tension. The ascending or descending liquid meniscus shall not change shape (i.e. it shall not crinkle at its edges). To ascertain whether a piece of glass a
