1、BRITISH STANDARD BS894:1956 Incorporating Amendment No.1 Specification for Ubbelohde apparatus for flow and drop points UDC 536.421.2:542.2BS894:1956 This BritishStandard, having been approved by the Scientific Glassware and Related LaboratoryApparatus Industry Standards Committee and endorsed by th
2、e Chairman of theChemical Divisional Council, was published under the authorityof the General Council on 30August1956 BSI 02-2000 First published April1940 First revision August1956 The following BSI references relate to the work on this standard: Committee reference LBC/1 Draft for comment CR(LBC)
3、6796 ISBN 0 580 34366 9 Co-operating organizations The Scientific Glassware and Related Laboratory Apparatus Industry Standards Committee, under whose supervision this BritishStandard was prepared, consists of representatives from the following Government departments and scientific and industrial or
4、ganizations: Admiralty* Air Ministry Association of British Chemical Manufacturers* Association of Scientific Workers Board of Trade British Association for the Advancement of Science* British Chemical Ware Manufacturers Association* British Laboratory Ware Association* British Lampblown Scientific
5、Glassware Manufacturers Association* British Pharmacopia Commission* British Scientific Instrument Research Association Chemical Society* Department of the Government Chemist* D.S.I.R.Chemical Research Laboratory Glass Manufacturers Federation Institute of Petroleum* Ministry of Education Ministry o
6、f Health* Ministry of Supply* National Physical Laboratory* Oil Companies Materials Committee Pharmaceutical Society of Great Britain Royal Institute of Chemistry* Science Masters Association Society for Analytical Chemistry* Society of Chemical Industry Society of Glass Technology* Standardization
7、of Tar Products Tests Committee* The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this BritishStandard: Association of Hospital M
8、anagement Committees D.S.I.R.Fuel Research Station D.S.I.R.Road Research Laboratory Guild of Public Pharmacists High Commission of India Metropolitan Water Board Oil and Colour Chemists Association Research Association of British Paint, Colour and Varnish Manufacturers University of London (Faculty
9、of Science) Individual manufacturers Amendments issued since publication Amd. No. Date of issue Comments 2627 November 1956 Indicated by a sideline in the marginBS894:1956 BSI 02-2000 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Assembly of apparatus 1 3 Meta
10、l cup 1 4 Thermometer for cup 1 5 Sleeve and case 1 6 Boiling tube 1 7 Cork 2 8 Beaker 2 9 Stirrer 2 10 Heating liquid 2 11 Auxiliary thermometer 2 12 Stand with clamps 2 13 Source of heat 2 14 Inscriptions 2 Appendix A Testing of BS Ubbelohde apparatus 3 Appendix B Examples of methods adopted for u
11、sing the Ubbelohde apparatus 3 Figure 1 Ubbelohde apparatusassembly 5 Figure 2 Ubbelohde cup 6 Figure 3 Ubbelohde apparatusthermometer and sleeve 7 Figure 4 Ubbelohde apparatuscase 8 Table 1 Dimensions of metal cup 1BS894:1956 ii BSI 02-2000 Foreword This standard makes reference to the following Br
12、itishStandard: BS593, Laboratory thermometers. This BritishStandard was first published in1940 under the title “Thedetermination of the flow and drop points of fats and allied substances,” and at that time only a glass cup was specified. In1947 an amendment was issued specifying a metal cup as an al
13、ternative, but it was pointed out that “it must not be assumed that the glass cups and metal cups may in all circumstances be used indiscriminately”, and experience has shown that the results obtained for a given material may differ significantly according to which type of cup is used. Similar appar
14、atus and methods of use have been specified both by the Institute of Petroleum and by the British Pharmacopia Commission. The Institute of Petroleum, however, have decided only to specify the metal cup, and in the1953 edition of the “British Pharmacopia” this has been introduced as an alternative to
15、 the glass cup. The chief objection to the latter is the difficulty of complying in manufacture with the precise tolerances on dimensions which are essential to secure interchangeability of the parts and reproducible results. Glass cups strictly complying with the BritishStandard have, in fact, been
16、 very difficult to obtain, and this consideration outweighs the advantage of the glass cup that air bubbles included during filling can be more easily detected. It has therefore been decided to specify only the metal cup in this revision. In order that the cup should be held firmly in the case and t
17、o secure interchangeability, both parts had previously to be made to very close tolerances, with consequent increase in cost. An important change in this edition is the provision on the case of spring clips which grip the cup. The tongues previously specified are not split, but are retained as guide
18、s for inserting the cup. Sleeves complying with the requirements of the1940 edition of this standard may still be used provided they are fitted with spring clips as specified. Other changes made in the apparatus specification are of minor importance. The previous edition contained a short section de
19、scribing the method of use, but enquiries have shown that the precise method of filling and using the cup needs to be specified in detail, and varies according to the type of material which is being tested. It is not possible in this BritishStandard to specify suitable methods for all materials, but
20、 for information and guidance the methods in use for a number of important materials are given in Appendix B. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British
21、 Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to8 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be in
22、dicated in the amendment table on the inside front cover.BS894:1956 BSI 02-2000 1 1 Scope This BritishStandard specifies a metal cup and ancillary apparatus of the Ubbelohde type for the determination of the flow and drop points of fats and allied substances. 2 Assembly of apparatus The apparatus sh
23、all consist of the following components: A. Metal cup. B. Thermometer for cup. C. Sleeve and case. D. Boiling tube. E. Cork. F. Beaker. G. Stirrer. H. Heating liquid. I. Auxiliary thermometer. J. Stand with clamps. K. Source of heat. The general assembly is shown in Figure 1. 3 Metal cup The cup sha
24、ll be made from chromium plated brass, or from other suitable metal which is not affected by the material being tested. The top of the cup and the bottom of the tube forming the orifice shall be smooth, parallel to each other and at right angles to the axis of the cup. The cup shall conform to the d
25、imensions given in Table 1 and Figure 2. The wide part of the cup shall have an approximately hemispherical lower portion, and an internal depth such that when a steel ball7.00mm in diameter is placed in the cup, the top of the ball shall be12.20 0.15mm above the bottom of the tube forming the orifi
26、ce. The bottom edge of the orifice shall not be chamfered or radiused. Table 1 Dimensions of metal cup 4 Thermometer for cup The thermometer used shall be a100mm immersion type selected as required from the ranges specified in Series C of BS593, 1)and shall comply with the relevant provisions in Tab
27、le2 or Table4 of that BritishStandard, except in so far as they conflict with the following special requirements: a) The diameter of the bulb shall be3.5 0.15mm. b) The length of the bulb shall be not more than6mm. c) The stem immediately above the bulb shall have a diameter approximately equal to,
28、but not less than that of the bulb, for a length of at least26mm, measured from the bottom of the bulb. d) The inscriptions on the thermometer shall be as given in Clause 14. e) The thermometer shall be finished with a plain top. Alternatively, where a particular thermometer is included in the speci
29、fication to which the product is being tested, then this thermometer shall be used. 5 Sleeve and case To the lower end of the thermometer the cylindrical metal sleeve seeFigure 3(a) shall be securely and coaxially cemented. 2)To this shall be screwed the metal case (seeFigure 4), which shall have tw
30、o small apertures, one in front and one behind, to act as air vents. The case shall have a rim stop, guide lugs to aid the coaxial insertion of the cup into the case, and spring clips which enable the cup to be retained firmly with its top edge against the stop. The design, dimensions, and method of
31、 fixing of the spring clips shown in Figure 4 are not mandatory but are recommended as suitable. The sleeve shall be fixed to the thermometer in such a position that, when the case is screwed on to the sleeve, the bottom of the thermometer bulb shall be8.0 0.1mm below the rim stop, and the thermomet
32、er stem shall be coaxial with the sleeve and case. 6 Boiling tube The boiling tube shall be of glass. Suitable dimensions for it are: Internal diameter of wide part External diameter of wide part Internal diameter of orifice External diameter of orifice Overall length mm 7.50 0.15 3.15 0.05 5.55 0.0
33、5 15.2 0.2 9.99 + 0.00 0.04 1) BS593, “Laboratory thermometers”. 2) While it does not form a mandatory part of this standard, it is suggested that the accurate location of the thermometer in the sleeve may be assisted by the use of a metal jig such as is shown in Figure 3(b). The inside of the sleev
34、e may with advantage be roughened to provide a key for the cement. The cement used shall be suitable for the temperatures covered by the thermometer. Overall length 110mm Internal diameter 25mmBS894:1956 2 BSI 02-2000 7 Cork The cork shall be approximately25mm long, shall be bored with a central hol
35、e to fit the thermometer specified in Clause4, and shall have a notch cut along the side. 8 Beaker The beaker shall be of glass, and of such a size that when the apparatus is assembled the boiling tube can be immersed vertically to two-thirds of its length in the liquid heating medium with its lower
36、 end about25mm above the bottom of the beaker. (A600ml squat form beaker is suitable.) 9 Stirrer The stirrer shall consist of any convenient device which will ensure uniformity of temperature throughout the liquid in the beaker. 10 Heating liquid Any suitable liquid may be used as the heating medium
37、 in the beaker. Water is recommended for flow and drop points below80 C and glycerine or liquid paraffin for flow and drop points above80 C. 11 Auxiliary thermometer Any suitable thermometer may be used for measuring the temperature of the heating liquid. A50mm immersion thermometer of suitable rang
38、e, constructed in accordance with the provisions for Series C of BS593, 3)is convenient for this purpose. 12 Stand with clamps Any suitable stand may be used to hold the boiling tube and auxiliary thermometer in position in the beaker, and to hold the beaker above a source of heat. 13 Source of heat
39、 Any suitable means may be used to heat the liquid in the beaker. 14 Inscriptions The metal cup specified in Clause3 and the thermometer specified in Clause4 shall each have permanently and legibly marked on it: a) An identification number. b) The makers or vendors name or mark. c) The number of thi
40、s BritishStandard, i.e.“BS894”. 4) 3) BS593, “Laboratory thermometers”. 4) The mark “BS894” on the product is an indication by the manufacturer that it purports to comply with the requirements of this BritishStandard. The BritishStandards Institution is the owner of the registered certification mark
41、 shown below: which can be used by manufacturers only under licence from the BSI. The presence of this mark in addition to the mark “BS894” on a product is an assurance that the product does comply with the requirements of the standard. It indicates that the BSI has satisfied itself, by inspection a
42、nd testing, that the system of production, supervision and control used by the manufacturer is such as to ensure compliance with all the requirements of the standard. Maintenance of this approved system is secured by periodical inspection and testing on behalf of the BSI. The mark must be accompanie
43、d by the name or registered trade mark or licence number of the licensed manufacturer. Further particulars of the terms of licence may be obtained from the Director, BritishStandards Institution,2 Park Street, London,W.1.BS894:1956 BSI 02-2000 3 Appendix A Testing of BritishStandard Ubbelohde appara
44、tus The National Physical Laboratory is prepared to accept metal cups and the thermometers for them for examination for compliance with the requirements of this BritishStandard. Particulars of the fees charged can be obtained on application to the Director, National Physical Laboratory, Teddington,
45、Middlesex. Appendix B Examples of methods adopted for using the Ubbelohde apparatus 1. British Pharmacopia1953. Melting point of hydnocarpus oil, soft paraffin, and wool fat. Method. The glass cup is filled with the substance and smoothed so that no air bubbles are included. The cup is then pushed,
46、without lateral movement, into the metal case as far as the stop and the excess fat squeezed out of the bottom of the tube is wiped away. Care is taken that the pressure equalizing aperture is not stopped. The thermometer, with the cup attached, is next fitted through the bored cork to the boiling t
47、ube, and the immersion line on the thermometer is adjusted to the top of the cork. The boiling tube is fixed vertically within the beaker so that at least two-thirds of its length is immersed in water contained in the beaker and kept stirred. The temperature of the outer bath is so adjusted that the
48、 temperature of the substance rises at the rate of1 C per minute. The temperature at which the first drop of melted liquid falls from the glass cup is regarded as the melting point of the substance. NOTEThe glass cup is that specified in earlier editions of BS894. The British Pharmacopia1953 also st
49、ates: “Alternatively, a metal cup of suitable dimensions may be used, provided that the result obtained is the same as that given when a glass cup complying with the above specification is used.” 2. Institute of Petroleum Standard Methods for Testing of Petroleum and its Products. Method I.P.31/55 Drop Point of Greases. Scope. In general, the drop point is an indication of the temperature of transition from the solid or semi-solid to the liquid state, and does not necessarily have any bearing upon service performance. Definition. The drop
