1、 ISO 2015 Laboratory glass and plastics ware Principles of design and construction of volumetric instruments Matriel de laboratoire en verre ou en plastique Principes de conception et de construction dinstruments volumtriques INTERNATIONAL STANDARD ISO 384 Second edition 2015-12-15 Reference number
2、ISO 384:2015(E) ISO 384:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, i
3、ncluding photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerla
4、nd Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 384:2015(E)Foreword iv 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Unit of volume and reference temperature 1 4.1 Unit of volume . 1 4.2 Reference temperature 1 5 Volumetric accuracy 1 6 Methods of
5、 calibration and use . 2 7 Construction 3 7.1 Material . 3 7.2 Wall thickness 3 7.3 Shape . 3 7.4 Capacity . 3 7.5 Stability 3 7.6 Delivery jets . 3 7.7 Stoppers 4 7.8 Stopcocks or similar devices . 4 8 Linear dimensions 4 9 Graduation lines 5 10 Scales 6 10.1 Spacing of graduation lines 6 10.2 Leng
6、th of graduation lines (see Figure 2) 6 10.2.1 General 6 10.2.2 Graduation pattern l . 6 10.2.3 Graduation pattern II . 6 10.2.4 Graduation pattern IIl . . 6 10.2.5 Special cases 7 10.3 Sequence of graduation lines (see Figure 1) . 7 10.4 Position of graduation lines (see Figure 2) 8 11 Figuring of
7、graduation lines . 9 12 Marking .10 13 V isibility of gr aduation lines, figur es and inscriptions .11 Annex A (normative) Maximum permissible error in relation to the inner diameter at the meniscus 12 Bibliography .15 ISO 2015 All rights reserved iii Contents Page ISO 384:2015(E) Foreword ISO (the
8、International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member 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
9、 has been established has the right to be represented on that committee. International organizations, governmental 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 electrotechnic
10、al standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in
11、 accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). 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.
12、Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute
13、an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committ
14、ee responsible for this document is ISO/TC 48, Laboratory equipment. This second edition cancels and replaces the first edition (ISO 384:1978), which has been technically revised to incorporate the following modifications. a) Volumetric instruments made from plastics have been added to the scope. b)
15、 Volumetric instruments of class AS have been added. c) The thickness of graduation lines has been modified. d) The basic principles for construction have been modified such that they comply with the product standards ISO 1042, ISO 648, ISO 835, ISO 385, ISO 4788 and ISO 4787. e) The relation betwee
16、n maximum permissible error and the inner diameter has been specified by an equation. f) Annex A, explaining that relation, has been reworded.iv ISO 2015 All rights reserved INTERNATIONAL ST ANDARD ISO 384:2015(E) Laboratory glass and plastics ware Principles of design and construction of volumetric
17、 instruments 1 Scope This International Standard sets out principles for the design of volumetric instruments manufactured from glass or from plastics in order to facilitate the most reliable and convenient use to the intended degree of accuracy. 2 Normative references The following documents, in wh
18、ole 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) applies. ISO 383, Laboratory glassware Interch
19、angeable conical ground joints ISO 4787, Laboratory glassware Volumetric instruments Methods for testing of capacity and for use ISO/IEC Guide 99, International vocabulary of metrology Basic and general concepts and associated terms (VIM) 3 T erms a nd definiti ons For the purposes of this document,
20、 the terms and definitions given in ISO/IEC Guide 99 apply. 4 Unit of volume and reference temperature 4.1 Unit of volume The unit of volume shall be the millilitre (ml), which is equivalent to one cubic centimetre (cm 3 ). 4.2 Reference temperature The standard reference temperature, i.e. the tempe
21、rature at which the volumetric instrument 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, this figure shall be substituted for 20 C. NOTE The capacity o
22、f volumetric instruments varies with change of temperature. A volumetric instrument which was adjusted at 20 C, but used at 27 C or vice versa, would show an extra error of only 0,007 % if it is made of borosilicate glass having a coefficient of cubic thermal expansion of 9,9 10 6C 1and of 0,02 % if
23、 it is made of soda-lime glass having a coefficient of cubic thermal expansion of 27 10 6C 1 . These errors are smaller than the limits of error for most volumetric instruments. It follows, therefore, that the reference temperature is of minor importance in practical use when dealing with glassware.
24、 However, when performing calibrations, it is important to refer to the reference temperature, especially when considering volumetric plastic ware. 5 Volumetric accuracy 5.1 There are two classes of accuracy: ISO 2015 All rights reserved 1 ISO 384:2015(E) the higher grade shall be designated “class
25、A” or “class AS”; the lower grade shall be designated “class B”. 5.2 The maximum permissible error shall be specified for each type of volumetric instrument in regard to the method and purpose of use and the class of accuracy. 5.3 The numerical values of maximum permissible error for volumetric inst
26、ruments for general purposes shall be preferably chosen from the series 10 12 15 20 25 30 40 50 60 80, or a suitable decimal multiple thereof. NOTE This series of preferred numbers has been adopted because decimal sub-multiples of some of the unrounded numbers, for example 31,5, would appear to impl
27、y a degree of precision which is not intended and which could not be measured in practice. 5.4 The maximum permissible error specified for a series of sizes of a volumetric instrument should provide a reasonably uniform progression in relation to capacity. 5.5 The maximum permissible error permitted
28、 for class B should, in general, be approximately twice as permitted for class A or AS. 5.6 For volumetric instruments having a scale, the maximum permissible error for either class of accuracy shall not exceed the volume equivalent (see Annex A) of the smallest scale division. 5.7 The maximum permi
29、ssible error MPE for class A or AS depends on the internal diameter D (in millimetres) at the related graduation line and shall not be smaller than derived by Formula (1): DD (1) The corresponding class B limit shall be derived in accordance with 5.5. NOTE The above formula applies for the most comm
30、on volumetric instruments which have a circular cross- section, but may be transferred to non-circular cross-sections as well. See Annex A. 5.8 In addition to 5.7, the maximum permissible error specified for any volumetric instrument designed to deliver shall also be not less than four times the sta
31、ndard deviation determined experimentally by an experienced operator from a series of at least 10 consecutive determinations of delivered capacity on the same volumetric instrument, carried out strictly in accordance with the method specified for this volumetric instrument in ISO 4787. 6 Methods of
32、calibration and use The method of calibration and use for each type of volumetric instrument is extensively described in ISO 4787. The general procedure is based upon a gravimetric determination of the volume of water, either contained in or delivered by the volumetric instrument under test. This vo
33、lume of water is calculated from its mass under consideration of air buoyancy and water density. Volumetric instruments manufactured from plastics should be considered to be calibrated more often than glass instruments, because of the lower long-term stability of plastic instruments.2 ISO 2015 All r
34、ights reserved ISO 384:2015(E) 7 Construction 7.1 Material Volumetric instruments shall be constructed of glass or plastic of suitable chemical and thermal properties. They shall be as free as possible from visible defects and shall be reasonably free from internal stress. 7.2 Wall thickness The vol
35、umetric instruments shall be sufficiently robust in construction to withstand usual laboratory usage and the wall thickness shall show no gross departure from uniformity. 7.3 Shape All volumetric instruments shall be of a shape which will facilitate the intended use, and should preferably be of circ
36、ular cross-section. 7.4 Capacity 7.4.1 The numerical values of capacity of volumetric instruments for general purposes should preferably be chosen from the series 10 20 25 50, or a decimal multiple or sub-multiple thereof. The capacity of volumetric instruments for special applications may have diff
37、ering values; there are e.g. pipettes with capacities of 3 ml to 9 ml. 7.4.2 The numerical value of the volume equivalents of the smallest division on volumetric instruments having a scale shall be chosen from the series 1 2 5, or a decimal multiple or sub-multiple thereof. 7.4.3 In the case of a sp
38、ecial purpose volumetric instrument which is to be graduated for direct reading of capacity when used with a specific liquid other than water, the specification should preferably indicate the corresponding capacity when used with pure water, so that the latter can be used for calibration. 7.5 Stabil
39、ity Volumetric instruments provided with a flat base shall stand vertically without rocking or spinning when placed on a level surface and, unless specified otherwise, the axis of the graduated portion of the vessel should be vertical. 7.6 Delivery jets 7.6.1 Delivery jets at the lower end of volume
40、tric instruments should be strongly constructed either with a smooth and gradual taper or a capillary end, both without sudden constriction at the orifice which could give rise to turbulent outflow. 7.6.2 The end of the jet shall be finished by one of the methods listed below in order of preference:
41、 a) hot finished square with the axis, slightly bevelled on the outside and polished; b) smoothly ground square with the axis and optionally fire-polished; c) cut square with the axis and polished. A fire-polished finish of glass jets reduces the danger of chipping in use, but should not result in s
42、udden constriction or in undue stress. ISO 2015 All rights reserved 3 ISO 384:2015(E) 7.6.3 The jet shall be made either from glass tubing or from suitable plastics material. It shall preferably form an integral part of the volumetric instrument. Otherwise, the jet shall be clearly identified to lin
43、k it to the related volumetric instrument or, if sufficient, to the nominal size of the volumetric instrument. 7.7 Stoppers 7.7.1 Glass stoppers should preferably be ground so as to be interchangeable, in which case the ground portions shall comply with ISO 383. lf individually fitted, they shall be
44、 well ground so as to prevent leakage, preferably with a taper of approximately 1:10. 7.7.2 Stoppers of a suitably inert plastics material may be permitted as an alternative to glass. In such cases, the glass or plastic socket into which the stopper fits should preferably comply with ISO 383. 7.8 St
45、opcocks or similar devices 7.8.1 Stopcocks and similar devices shall be designed to permit smooth and precise control of outflow and to prevent a rate of leakage greater than that allowed in the specification for the volumetric instrument. 7.8.2 Stopcocks and similar devices shall be made from glass
46、 or from suitable inert plastics material. 7.8.3 All-glass stopcocks shall have the key and barrel finely ground preferably to a taper of 1:10 and shall comply with appropriate national or international specifications. 7.8.4 Glass stopcock barrels to receive plastics keys shall be polished internall
47、y and may have a taper of 1:5 or 1:10. 7.8.5 Stopcock components may be fitted with suitable retaining devices. 8 Linear dimensions 8.1 Linear dimensional requirements shall be specified for all volumetric instruments in such a way as to ensure that: a) the volumetric instrument is convenient and sa
48、tisfactory for its intended use; b) in a series of sizes of a volumetric instrument, unnecessary inconsistencies in shape and proportions can be avoided; c) a limitation is placed on the maximum inner diameter at the graduation line or lines (see 5.7 and Annex A). This limitation may be a direct lim
49、itation on the inner diameter or an indirect one by a minimum limitation on scale length; d) the requirement for spacing of graduation lines specified in 10.1.2 is achieved; e) the stability requirements of 7.5 can be achieved. 8.2 Dimensional requirements should not be more restrictive than is necessary to achieve the aims listed in 8.1. Linear dimensions shall be specified in millimetres. 8.3 In order to permit maximum freedom in manufacture within the restrictions imposed
