1、July 2007DEUTSCHE NORM English price group 11No 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!,yh$“9866901www
2、.din.deDDIN EN ISO 835Laboratory glassware Graduated pipettes (ISO 835:2007)English version of DIN EN ISO 835:2007-07Laborgerte aus Glas Messpipetten (ISO 835:2007)Englische Fassung DIN EN ISO 835:2007-07SupersedesDIN 12695:1975-04,DIN 12696:1975-04 andDIN 12697:1975-04www.beuth.deDocument comprises
3、 17 pages 10.07DIN EN ISO 835:2007-07 2 National foreword This standard has been published in agreement with the Physikalisch-Technische Bundesanstalt (PTB) Braunschweig and Berlin. This standard has been published in accordance with a decision taken by CEN/TC 332 “Laboratory equipment” (Secretariat
4、: DIN, Germany) to adopt, without alteration, International Standard ISO 835 as a European Standard. The responsible German body involved in its preparation was the Normenausschuss Laborgerte und Labor-einrichtungen (Laboratory Equipment Standards Committee), Technical Committee Volumenmessgerte. Th
5、e DIN Standards corresponding to the International Standards referred to in clause 2 and in the bibliography of the EN are as follows: ISO 384:1978 DIN ISO 384:1978-12 ISO 719 DIN ISO 719 ISO 1769 DIN 12621 ISO 8655-2 DIN EN ISO 8655-2 Amendments This standard differs from DIN 12695:1975-04, DIN 126
6、96:1975-04 and DIN 12697:1975-04 as follows: a) The different types of graduated pipettes are now covered in one standard. b) Nominal capacities, graduations and maximum permissible errors have been amended. c) Some dimensions have been changed. d) The waiting time for class AS pipettes has been red
7、uced from 15 seconds to 5 seconds. e) Procedures for conformity testing have been specified. Previous editions DIN DENOG 54: 1930-03 DIN 12695: 1941-07, 1959-09, 1975-04 DIN 12696: 1941-07, 1959-09, 1975-04 DIN 12697: 1971-07, 1975-04 National Annex NA (informative) Bibliography DIN 12621, Colour ma
8、rking of pipettes Arrangements, dimensions, characterizing colours DIN EN ISO 8655-2, Piston-operated volumetric apparatus Part 2: Piston pipettes DIN ISO 384:1978-12, Laboratory glassware Principles of design and construction of volumetric glassware DIN ISO 719, Glass Hydrolytic resistance of glass
9、 grains at 98 C Method of test and classification EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM April 2007 ICS 17.060 English Version Laboratory glassware - Graduated pipettes (ISO 835:2007) Verrerie de laboratoire - Pipettes gradues (ISO 835:2007) Laborgerte aus Glas - Messpipetten (ISO 835:200
10、7) This European Standard was approved by CEN on 13 March 2007. 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 re
11、ferences concerning such national standards 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 memb
12、er into its own language and notified to 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, L
13、atvia, Lithuania, Luxembourg, Malta, Netherlands, 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 B
14、russels 2007 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 835:2007: EEN ISO 835 2 Contents 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
15、 volume .5 4.3 Reference temperature5 5 Types and classes of accuracy5 5.1 Classes of accuracy 5 5.2 Types of pipettes .5 6 Maximum permissible errors6 7 Construction.7 7.1 Material .7 7.2 Dimensions.7 7.3 Top of pipette .7 7.4 Delivery jet7 7.5 Delivery time.8 7.6 Waiting time8 8 Graduation, figuri
16、ng and patterns8 8.1 Graduation patterns.8 8.2 Position of graduation lines .8 8.3 Figuring of graduation lines .8 9 Setting of the meniscus 9 10 Marking .9 11 Visibility of graduation lines, figures and inscriptions. 10 12 Colour coding 10 Annex A (normative) Definition of capacities and delivery t
17、imes. 11 Bibliography. 15 EN ISO 835:2007 (E)Foreword This document (EN ISO 835:2007) has been prepared by Technical Committee ISO/TC 48 “Laboratory glassware and related apparatus” in collaboration with Technical Committee CEN/TC 332 “Laboratory equipment”, the secretariat of which is held by DIN.
18、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 October 2007, and conflicting national standards shall be withdrawn at the latest by October 2007. According to the CEN/CENELEC Internal Regulations
19、, 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, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands
20、, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 835:2007 has been approved by CEN has EN ISO 835:2007 without any modifications. 3 EN ISO 835:2007 (E)1 Scope This International Standard specifies metrological
21、and constructional requirements for graduated pipettes, adequate for general laboratory purposes. The details specified are in conformity with the principles of design and construction of volumetric glassware given in ISO 384. NOTE For one-mark pipettes, see ISO 648. For piston-operated pipettes, se
22、e ISO 8655-2. 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 (including any amendments) applies. ISO 384:1978
23、, 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 classification ISO 1769, Laboratory glassware Pipettes Colour coding ISO 3696, Water for analytical laboratory use Specification and te
24、st 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 the pipette NOTE Due to retention of liquid on the inner surface of the pipette, the volume of liquid delivered is not identical with
25、the volume of liquid contained by the pipette. 3.2 delivery time time required for the pipette to deliver its nominal volume 3.3 waiting time time to be observed after apparent completion of the liquid delivery of the pipette and before the final reading of the delivered volume is taken NOTE A waiti
26、ng time applies for graduated pipettes of Class AS (see 5.1 and 7.6). 4 EN ISO 835:2007 (E)4 Basis of adjustment 4.1 Unit of volume The unit of volume shall be the millilitre (ml) which is equivalent to the cubic centimetre (cm3). 4.2 Delivery volume Graduated pipettes shall be adjusted with water a
27、ccording to ISO 3696, grade 3, to deliver their specified volume (Ex). The delivery should be under gravity and unrestricted. For details, see 7.5. 4.3 Reference temperature The standard reference temperature, i.e. the temperature at which the pipette is intended to deliver its volume, shall be 20 C
28、. 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 and classes of accuracy 5.1 Classes of accuracy Two classes of accuracy are spe
29、cified: Classes A and AS for the higher grade; Class B for the lower grade. The maximum permissible errors for both classes are specified in Table 1. The pipettes shall be adjusted as follows: Class A: without waiting time; Class AS: with a specified waiting time of 5 s (see 7.6); Class B: without w
30、aiting time. 5.2 Types of pipettes 5.2.1 Type 1: Partial delivery Graduated pipettes adjusted for delivery of a liquid from zero line at the top to any graduation line; nominal capacity shall be represented by the lowest graduation line. 5.2.2 Type 2: Total delivery Graduated pipettes adjusted for d
31、elivery of a liquid from any graduation line down to the jet; nominal capacity shall be represented by the highest graduation line. 5 EN ISO 835:2007 (E)5.2.3 Type 3: Total delivery Graduated pipettes adjusted for delivery of a liquid from zero line at the top to any graduation line; nominal capacit
32、y shall be obtained by delivery down to the jet. 5.2.4 Type 4: Blow-out Graduated pipettes for total delivery (see Type 3) where the last drop of liquid in the jet is expelled by blowing. Blow-out pipettes shall be adjusted to accuracy Class B. 6 Maximum permissible errors Maximum permissible errors
33、 in the delivered volume shall not exceed the limits specified in Table 1. These limits represent the maximum permitted error at any point and also the maximum permissible difference between the errors at any two points. Table 1 Capacities, subdivisions and maximum permissible errors Nominal capacit
34、y Smallest scale division Maximum permissible error ml ml Classes A and AS ml Class B ml 0,1 0,01 0,006 0,01 0,2 0,01 0,006 0,01 0,5 0,01 0,006 0,01 1 0,01 0,007 0,01 1 0,10 0,007 0,01 2 0,02 0,010 0,02 2 0,10 0,010 0,02 5 0,05 0,030 0,05 5 0,10 0,030 0,05 10 0,1 0,05 0,1 20 0,1 0,1 0,2 25 a0,1 0,1
35、0,2 25 0,2 0,1 0,2 aLength 450 mm, see Table 2. If graduated pipettes are required of capacities and/or subdivisions other than those listed in Table 1, they shall conform to the essential requirements of this International Standard. The relationships between maximum permissible error and capacity,
36、as well as between maximum permissible error and meniscus diameter as given in ISO 384:1978, Annex A and Annex B, shall be observed. 6 EN ISO 835:2007 (E)7 Construction 7.1 Material Graduated pipettes shall be manufactured from glass of chemical resistance and thermal properties which are at least t
37、o class HGB3 in accordance with ISO 719, and shall be as free as possible from visible defects and shall be reasonably free from internal stress. 7.2 Dimensions Graduated pipettes shall comply with the essential dimensional requirements shown in Table 2. Table 2 Dimensions Nominal capacity ml Dimens
38、ions mm 0,1 0,2 0,5 1 2 5 10 20 25 25 Smallest scale division ml 0,01 0,01 0,01 0,010,100,020,100,050,100,1 0,1 0,1 0,2 Essential dimensions Distance from zero line to lowest graduation line for Type 1 pipettes min. max. 80170 120200 130220 160 220 160 220 140220 140 220 140 220 220 290 180220 Dista
39、nce from highest to lowest figured graduation lines for Types 2, 3 and 4 pipettes min. max. 70160 110190 110 220 140 220 140 220 140220 140 220 140 220 200 290 160 220 Distance from highest graduation line to top of pipette min. 100 External diameter of suction tube approx. 5,25 to 9 5,5 to 9 Length
40、 of tube of uniform bore below lowest graduation line min. 5 Recommended dimensions Overall length approx. 300 340 360 360 360 360 360 360 450 360 Length of tapered portion forming jet approx. 15 15 20 20 20 25 25 30 30 30 Wall thickness approx. 2 2 2 2 1,5 1 1 1 1 1 7.3 Top of pipette The top of th
41、e graduated 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 by the finger, in setting the meniscus. The end may be lightly fire-polished or smoothly ground
42、with a slight bevel on the outside. The upper end of the pipette tube may be made from tubing of uniform bore or may have a constriction at about 25 mm below the top to enable the retention of a porous, air-permeable plug, such as a cotton plug. 7.4 Delivery jet The lower end of the graduated pipett
43、e shall terminate either in a delivery jet having a smooth and gradual taper or in a capillary end, both without sudden constriction 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 EN ISO 835:200
44、7 (E)7.5 Delivery time The delivery time is defined as the time occupied by the free descent of the water meniscus (delivery under gravity) from the highest graduation line: to the lowest graduation line, in the case of Type 1 graduated pipettes; to the point at which the meniscus appears to come to
45、 rest in the jet, in the case of Type 2, Type 3 and Type 4 graduated pipettes. For testing of the delivery time, the clean graduated pipette shall be held in a vertical position, if appropriate with no porous, air-permeable plug fitted, and filled with water to a few millimetres above the uppermost
46、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 touching the tip of the jet against the inner surface of an inclined glass vessel. Delivery shall then be made into another glass vessel (the receiving vessel), so th
47、at the tip of the jet is in contact with the inner surface of this receiving vessel, above the level of any collected liquid, but without movement of one against the other throughout the delivery period. IMPORTANT It is important that a glass receiving vessel is used. Capillary effects influencing t
48、he delivery time depend considerably on the material on which the liquid runs down. The delivery time thus determined shall be within the limits specified for the particular pipette (see Annex A). In the case of Type 4 (blow-out) graduated pipettes, the last drop of liquid shall be expelled by blowi
49、ng after observing a delay time of approximately 3 s. 7.6 Waiting time The waiting time of 5 s specified for Class AS graduated pipettes is defined as the period of time to be observed in order to ensure complete delivery after the meniscus appeared to come to rest in the jet, and before the tip of the jet is removed from the inner surface of the receiving vessel. The waiting time of 5 s shall be marked on the pipette see 10.1 e) by the manufacturer. 8 Graduation, figuring and patterns 8.1 Graduation patterns All graduated
