1、January 2009DEUTSCHE NORM English price group 8No part of this standard 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 71.040.20!$UQ$“1504601w
2、ww.din.deDDIN EN ISO 648Laboratory glassware Single-volume pipettes (ISO 648:2008)English version of DIN EN ISO 648:2009-01Laborgerte aus Glas Vollpipetten (ISO 648:2008)Englische Fassung DIN EN ISO 648:2009-01SupersedesDIN 12690:1975-04 andDIN 12691:1975-04www.beuth.deDocument comprises 13 pagesDIN
3、 EN ISO 648:2009-01 2 National foreword This standard has been prepared by Technical Committee ISO/TC 48 “Laboratory equipment”, Subcommittee SC 6 “Laboratory and volumetric ware” in collaboration with Technical Committee CEN/TC 332 “Laboratory equipment” (Secretariat: DIN). The responsible German b
4、ody involved in its preparation was the Normenausschuss Laborgerte und Laboreinrichtungen (Laboratory Devices and Installations Standards Committee), Technical Committee NA 055-01-08 AA Volumenmessgerte. This standard has been published in agreement with the Physikalisch-Technische Bundesanstalt (PT
5、B) Braunschweig and Berlin. The DIN Standards corresponding to the International Standards referred to in clause 2 and in the bibliography of this document are as follows: ISO 384:1978 DIN ISO 384:1978-12 ISO 385 DIN EN ISO 385 ISO 719 DIN ISO 719 ISO 835 DIN EN ISO 835 ISO 1769 DIN 12621 ISO 3696 D
6、IN ISO 3696 ISO 4797 DIN ISO 4797 ISO 8655-2 DIN EN ISO 8655-2 Amendments This standard differs from DIN 12690:1975-04 and DIN 12691:1975-04 as follows: a) Different types of single-volume pipettes have been combined in one standard. b) Two-mark pipettes have been added. c) Some dimensions have been
7、 modified. d) The waiting time for Class AS pipettes has been reduced from 15 s to 5 s. e) Test methods have been given in more detail. f) Requirements relating to packaging have been deleted. Previous editions DIN DENOG 53: 1929-08 DIN 12690: 1941-07, 1960-04, 1975-04 DIN 12691: 1975-04 EUROPEAN ST
8、ANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 648 October 2008 ICS 17.060 English Version Laboratory glassware - Single-volume pipettes (ISO 648:2008) Verrerie de laboratoire - Pipettes un volume (ISO 648:2008) Laborgerte aus Glas - Vollpipetten (ISO 648:2008) This European Standard was approved by
9、CEN on 4 October 2008. 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 standar
10、ds may be obtained on application to the CEN 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
11、the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Neth
12、erlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitati
13、on in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 648:2008: EContents 2 DIN EN ISO 648:2009-01 EN ISO 648:2008 (E)Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Basis of adjustment.5 4.1 Unit of volume5 4.2 Delivery volume .5
14、 4.3 Reference temperature5 5 Types and classes of accuracy5 5.1 Classes of accuracy 5 5.2 Types of single-volume pipette5 6 Maximum permissible errors6 7 Construction.6 7.1 Material .6 7.2 Shape 6 7.3 Bulb .6 7.4 Dimensions.7 7.5 Top of pipette .8 7.6 Delivery jet8 7.7 Delivery time.8 7.8 Waiting t
15、ime9 8 Graduation line(s) 9 9 Setting of the meniscus 9 10 Marking .9 11 Visibility of graduation lines, figures and inscriptions. 10 12 Colour coding 10 Bibliography. 11 Foreword 3 EN ISO 648:2008 (E)DIN EN ISO 648:2009-01 This document (EN ISO 648:2008) has been prepared by Technical Committee ISO
16、/TC 48 “Laboratory equipment” in collaboration with 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
17、April 2009, and conflicting national standards shall be withdrawn at the latest by April 2009. 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
18、 rights. 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland
19、, 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 648:2008 has been approved by CEN as a EN ISO 648:2008 without any modification. 1 Scope This Inter
20、national Standard specifies metrological and constructional requirements for volumetric pipettes with one mark (total delivery) and for volumetric pipettes with two marks, both of which are adequate for general laboratory purposes. The details specified are in conformity with the principles of desig
21、n and construction of volumetric glassware given in ISO 384. NOTE For graduated pipettes, see ISO 835. For piston-operated pipettes, see ISO 8655-2. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the editio
22、n cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 384:1978, Laboratory glassware Principles of design and construction of volumetric glassware ISO 719, Glass Hydrolytic resistance of glass grains at 98 C Method of test and
23、classification ISO 1769, Laboratory glassware Pipettes Colour coding ISO 3696, Water for analytical laboratory use Specification and test methods 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 delivery volume volume of liquid discharged from
24、 the pipette NOTE Due to retention of liquid on the inner surface of the volumetric instrument, the volume of liquid delivered is not identical with the volume of liquid contained by the volumetric instrument. 3.2 delivery time time required for the descent of the liquid meniscus from the graduation
25、 line to the point at which the meniscus appears to come to rest in the jet for one-mark pipettes and from the upper graduation line to the lower graduation line for two-mark pipettes 3.3 waiting time time to be observed after apparent completion of the liquid delivery of the volumetric instrument N
26、OTE A waiting time applies for Class AS single-volume pipettes (see Clause 5 and 7.8). 4 DIN EN ISO 648:2009-01 EN ISO 648:2008 (E)4 Basis of adjustment 4.1 Unit of volume The unit of volume shall be the millilitre (ml), which is equivalent to one cubic centimetre (cm3). 4.2 Delivery volume Single-v
27、olume pipettes shall be adjusted with water of grade 3 quality, in accordance with to ISO 3696, to deliver their nominal volume (Ex). The delivery should be under gravity and unrestricted. For details, see 7.7 and 7.8. 4.3 Reference temperature The standard reference temperature, i.e. the temperatur
28、e at which the pipette is intended to deliver its nominal volume, shall be 20 C. When the pipette 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 20 C. 5 Types
29、and classes of accuracy 5.1 Classes of accuracy Two classes of accuracy are specified: Class A and AS for the higher grade; Class B for the lower grade. 5.2 Types of single-volume pipette The following two types of single-volume pipettes are specified: those for which no waiting time is specified (C
30、lasses A and B); those for which a waiting time of 5 s is specified (Class AS). 5 EN ISO 648:2008 (E)DIN EN ISO 648:2009-01 6 Maximum permissible errors Maximum permissible errors in the delivered volume shall not exceed the limits specified in Table 1. Table 1 Nominal volumes and maximum permissibl
31、e errors Maximum permissible error Nominal volume Class A and AS Class B ml ml ml 0,5 0,005 0,010 1 0,008 0,015 2 0,010 0,02 5 0,015 0,03 10 0,02 0,04 20 0,03 0,06 25 0,03 0,06 50 0,05 0,10 100 0,08 0,15 The relationships between maximum permissible error and nominal volume, as well as between maxim
32、um permissible error and meniscus diameter as given in ISO 384:1978, Annex A and Annex B, shall be observed. For the maximum permissible errors of single-volume pipettes with intermediate nominal volumes between those given in Table 1, the value for the nearest nominal volume shall apply. If the int
33、ermediate volume is exactly halfway between those given in Table 1, the value for the next greater nominal volume shall apply. 7 Construction 7.1 Material Single-volume pipettes shall be manufactured from glass of chemical resistance and thermal properties at least to HGB3 in accordance with ISO 719
34、, shall be as free as possible from visible defects and reasonably free from internal stress. 7.2 Shape Pipettes of 0,5 ml nominal volume shall consist of a straight tube with a jet at the lower end. Pipettes of nominal volume 1 ml and 2 ml may be of similar straight tube pattern or may alternativel
35、y be of bulb pattern, as described herein for the larger sizes. All larger pipettes shall consist of a bulb with suction and delivery tubes, the three portions being straight and coaxial. 7.3 Bulb The main portion of the bulb shall be cylindrical, except that 1 ml and 2 ml nominal-volume pipettes ma
36、y have an oval bulb if desired. The two ends of the bulb shall merge gradually into the suction and delivery tubes, the junctions being of tapered formation to facilitate drainage. 6 DIN EN ISO 648:2009-01 EN ISO 648:2008 (E)7.4 Dimensions Single-volume pipettes shall comply with the dimensional req
37、uirements shown in Tables 2, 3 and 4. Table 2 Dimensions Nominal volume ml Dimensions mm 0,5 1 2 5 10 20 25 50 100 Overall length max. 300 325 350 410 450 520 530 550 600 Internal diameter at the graduation line max. 2,5 3,5 4,5 4,5 5 5,5 5,5 6 7,5 Length of suction tube valid only for bulb pattern
38、pipettes min. 150 150 150 160 170 170 170 170 Length of delivery tube valid only for bulb pattern pipettes min. 110 125 145 160 210 220 230 240 External diameter of delivery tube valid only for bulb pattern pipettes 1 5 6 6,5 7 7 7 8 9 External diameter of bulb valid only for bulb pattern pipettes m
39、ax. 9 9 12 16 22 24 30 38 External diameter of tube valid only for straight pattern pipettes max. 5 6 7 Table 3 Dimensions applying to all nominal volumes of one-mark pipettes Dimension Size mm Distance of graduation line from top of pipette min. 100 Distance from graduation line to top of bulba min
40、. 10 Distance from graduation line to tip of jet valid only for straight pattern pipettes min. 110 Wall thickness bulb pattern pipettes straight pattern pipettes min. min. 0,6 0,8 aTop of bulb relates to the point at which the suction tube begins to expand into the bulb.7 EN ISO 648:2008 (E)DIN EN I
41、SO 648:2009-01 Table 4 Dimensions applying to all nominal volumes of two-mark pipettes Dimension Size mm Distance of upper graduation line from top of pipette min. 100 Distance from upper graduation line to top of bulba min. 10 Distance from upper graduation line to tip of jet valid only for straigh
42、t pattern pipettes min. 110 Distance from lower graduation line to bottom of bulba min. 20 Distance from lower graduation line to tip of jet min. 30 Wall thickness bulb pattern pipettes straight pattern pipettes min. min. 0,6 0,8 aTop of bulb and bottom of bulb relate to the points at which the suct
43、ion tube and the delivery tube begin to expand into the bulb.7.5 Top of pipette The top of the single-volume pipette shall lie in a plane at right angles to the axis of the pipette and shall be free from any blemishes which might interfere with the required accurate control by a mechanical device or
44、 by the finger in setting the meniscus. The end may be lightly fire-polished or smoothly ground with a slight bevel on the outside. 7.6 Delivery jet The lower end of the pipette shall terminate either in a delivery jet having a smooth and gradual taper or in a capillary end, both without sudden cons
45、triction at the orifice which could give rise to turbulent outflow. The end of the jet may be finished by grinding or machine tooling and may be fire-polished. 7.7 Delivery time For testing of the delivery time, the clean pipette shall be held in a vertical position and filled with de-ionized water
46、to a few millimetres above the (upper) graduation line; the falling meniscus shall then be set to this line. Any drop adhering to the jet of the pipette shall be removed by bringing the surface of a glass vessel into contact with the tip of the jet. Delivery shall then be made into another glass ves
47、sel which is slightly inclined so that the tip of the jet is in contact with the inside of the vessel, but without movement of one against the other throughout the delivery period. For one-mark pipettes, delivery shall be made from the graduation line down to the jet of the pipette. For two-mark pip
48、ettes, delivery shall be made from the upper graduation line down to the lower graduation line. IMPORTANT It is important that a glass receiving vessel be used. Capillary effects influencing the delivery time depend considerably on the material down which the water runs. 8 DIN EN ISO 648:2009-01 EN
49、ISO 648:2008 (E)The delivery time thus determined, in seconds, shall be within the limits specified in Table 5. Table 5 Delivery times in seconds Nominal volume ml 0,5 1 2 5 10 20 25 50 100 Class A min. max. 10 20 10 20 10 25 15 30 15 40 25 50 25 50 30 60 40 60 Class AS min. max. 6 10 7 11 7 11 9 13 11 15 12 16 15 20 20 25 25 30 Class B min. max. 4 20 5 20 5 25 7 30 8 40 9 50 10 50 13 60 25 60 Maximum permissible difference between observed and marked delivery times max. 2 2 2 3 3 4
