ISO-7884-6-1987.pdf
《ISO-7884-6-1987.pdf》由会员分享,可在线阅读,更多相关《ISO-7884-6-1987.pdf(8页珍藏版)》请在三一文库上搜索。
1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOAHAR OPrAHM3AMR ll0 CTAHFAPTM3Al. f 1: h e Glass - Viscosity and viscometric fixed points - Part 6 : Determination of softening point SO 7884-6 Grst edition 987-12-15 Reference
2、 number IS0 7884-6 : 1987 (E) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 20:56:53 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword IS0 (the
3、 International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committe
4、e has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for appro
5、val before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 7664-6 was prepared by Technical Committee ISO/TC 46, Laboratory glassware and relat
6、ed apparatus. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. 0 International Organization for Standardization, 1997 0 Printed in Switzerl
7、and Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 20:56:53 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 7664-6 : 1987 (E
8、) Glass - Viscosity and viscometric fixed points - Part 6 : Determination of softening point 0 Introduction International Standard IS0 7664, Glass - Viscosity and viscometric fixed points, consists of the following separate parts : Part 7 : Principles for determining viscosity and viscometric fixed
9、points. Part 2 : Determination of viscosity by rotation viscometers. Part 3 : Determination of viscosity by fibre elongation viscometer. Part 4 : Determination of viscosity by beam bending. Part 5 : Determination of working point by sinking bar viscometer. Part 6 : Determination of softening point.
10、Part 7 : Determination of annealing point and strain point by beam bending. Part 8 : Determination of ldilatometricl transformation temperature. 1 Scope This part of IS.0 7884 specifies a method of determining the softening point of a glass. It has been found useful as a control test to indicate cha
11、nges in composition, for specification ac- ceptance and for providing information in research and development work with glass. 2 Field of application This method is applicable to all glasses of normal bulk- production compositions unless devitrification takes place dur- ing the preparation or testin
12、g of the specimen. The softening points range between 370 and 1 000 OC, depen- ding on the type of glass. 3 Reference IEC Publication W-1, Thermocouples - Part 1 : Reference tables. 4 Definition For the purposes of this part of IS0 7884, the following defini- tion applies. softening point, dr2 : App
13、roximately the temperature above which the glass is capable of most forming operations. NOTES 1 A viscosity of about 107,s dPa.s* may be assigned to the softening point for glass of density Q = 2,5 g/cm3 and surface tension G = 300 mN/m. (For glasses with other values of density or surface tension,
14、see IS.0 7884-l .I 2 The softening point is also called the Littleton temperature. 5 Principle Determination of the temperature at which a round fibre of the glass, nominally 0,65 mm in diameter and 235 mm long with specified tolerances, elongates under its own weight at a rate of 1 mm/min when the
15、upper 100 mm of its length is heated in a specified furnace at the rate of (5 + 1) Wmin. NOTE - In principle, the device used in this method corresponds to a fibre elongation viscometer (see IS0 7884-3). Closely defined re- quirements for the test specimen, procedure and apparatus lead to a good rep
16、eatability of the specified temperature point. The related viscosity value, however, is of less certainty. 6 Apparatus 6.1 Furnace The furnace shall conform in all essential respects to the re- quirements shown in the annex. Equivalent material may be employed, where available. dN.s * 1 dPa.s = 1 ,2
17、 = 1 P (P is the symbol for poise) 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 20:56:53 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7664-6
18、 : 1987 (El 6.2 Furnace stand A means shall be provided for supporting the furnace so that the fibre hangs below it. This stand shall be provided with a levelling device such as three screws. The stand shown in the annex is convenient when used with either a cathetometer or a telescope and scale. 6.
19、3 Heating rate controller Suitable controls shall be provided for maintaining the furnace heating rate at (5 k 1) Urnin. NOTE - A continuously adjustable transformer has proved effective for controlling the heating rate. 6.4 Temperature measuring and indicating instruments 6.4.1 The alumina-insulate
20、d platinum-10 % rhodium/platinum (type S according to IEC 564-l) thermocouples, or nickel- chromium/nickel (type K according to IEC 564-l) ther- mocouples placed in a double-bore porcelain tube in accor- dance with the diagram in the annex shall exhibit low thermal inertia (the diameter of the wires
21、 should not be greater than 0,5 mm). 6.4.2 The measurement thermocouple shall be placed in the furnace core in accordance with the specifications in the annex (No. 4 and 17). In accordance with IS0 7664-1, the measure- ment thermocouples shall be calibrated and the calibration checked regularly. 6.4
22、.3 The electrical output of the thermocouples shall be determined at zero current by means of potentiometers, or high-resistance electronic amplifiers having a sensitivity of 1 pV for type S (according to IEC 564-l), or 4 pV for type K (accor- ding to IEC 564-I) thermocouples. Precautions shall be t
23、aken that the ice-bath for the cold junction is maintained at 0 OC throughout the test. If the temperature measuring equipment is fitted with automatic cold junction compensation, the ice-bath can be omitted. 6.5 Fibre elongation measurement equipment The fibre elongation shall be measured using a d
24、evice capable of measuring the position of the end of the fibre within 0,02 mm throughout the entire elongation period. NOTE - Suitable devices that have proved effective for measuring the elongation are of both optical and electronic types. For some devices it may be convenient if they are fixed wi
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ISO 7884 1987
链接地址:https://www.31doc.com/p-3779177.html