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1、BRITISH STANDARD BS 756:1952 Incorporating Amendment Nos. 1 and 2 Dean and stark apparatus Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:30:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 756:1952 This British Standard, having been approved by the Scientif
2、ic Glassware and Related Laboratory Apparatus Industry Standards Committee and endorsed by the Chairman of the Chemical Divisional Council, was published under the authority of the General Council on 5 December 1952 BSI 03-2000 First published November 1937 First revision May 1939 Second revision De
3、cember 1952 ISBN 0 580 35247 1 Co-operating organizations The Scientific Glassware and Related Laboratory Apparatus Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and indus
4、trial organizations: 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 Sci
5、entific 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
6、Ministry of Health* Ministry of Supply* National Physical Laboratory* Oil Companies Materials Committee Pharmaceutical Society of Great Britain Royal Institute of Chemistry* Science Masters Association Society of Chemical Industry Society of Glass Technology* Society of Public Analysts and Other Ana
7、lytical Chemists* Standardization 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 British
8、Standard: Association of Hospital Management Committees D.S.I.R. Fuel Research Station D.S.I.R. Road Research Laboratory Guild of Public Pharmacists Metropolitan Water Board Office of the High Commissioner for India Oil and Colour Chemists Association Research Association of British Paint, Colour an
9、d Varnish Manufacturers University of London (Faculty of Science) Individual manufacturers Amendments issued since publication Amd. No.Date of issueComments 1778December 1953 4882July 1985Indicated by a sideline in the margin Licensed Copy: London South Bank University, London South Bank University,
10、 Fri Dec 08 13:30:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 756:1952 BSI 03-2000i Contents Page Co-operating organizationsInside front cover Forewordii 1Scope1 2Assembly of apparatus1 3Material1 4Design and dimensions1 5Distillation vessel1 6Condenser1 7Receiver1 Appendix Testing of BS Dean a
11、nd Stark receivers5 Figure 1 Typical assembly of Dean and Stark apparatus6 Figure 2 Flanged joint suitable for use with metal distillation vessel7 Figure 3 Condenser8 Figure 4 Spray tube9 Figure 5 2 ml. receiver10 Figure 6 7.5 ml. receiver11 Figure 7 10 ml. receiver12 Figure 8 25 ml. receiver withou
12、t stopcock13 Figure 9 25 ml. receiver with stopcock14 Figure 10 100 ml. receiver15 Figure 11 3 ml. Type 2 receiver16 Figure 12 12.5 ml. Type 2 receiver17 Table 1 Sizes and connections of receivers for dean and stark apparatus2 Table 2 Mandatory dimensions and tolerances for dean and stark receivers2
13、 Table 3a Recommended dimensions for dean and stark receivers (Types 1 and 2)3 Table 3b Recommended dimensions for dean and stark receivers (Type 2 only)4 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:30:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 756:
14、1952 ii BSI 03-2000 Foreword This standard makes reference to the following British Standards: BS 572, Interchangeable conical ground glass joints. BS 1751, General purpose glass stopcocks. Apparatus of the Dean and Stark type was first specified in 1936, when BS 614 “Graduated receivers for Dean an
15、d Stark apparatus” was published. At that time ground glass joints were not specified, but in 1937 was added BS 756, “Apparatus for the determination of small quantities of water by distillation with an immiscible liquid”, which included requirements for condenser, receiver and flask with ground joi
16、nt connections. In 1939, when the two specifications were combined as a revision of BS 756, standard ground joints were becoming popular, but were still considered somewhat of a luxury in many laboratories; although it was recognized that their use afforded greater accuracy in the apparatus in quest
17、ion, it was still considered advisable on the score of cheapness to provide for the use of corks, despite their shortcomings. In the present revision, however, standard joints only are specified for the connection to the condenser, although there is, for most sizes, a choice of standard joint or cor
18、k for the connection to the distillation vessel. A further change is the introduction of the B19 joint for the connection between condenser and receiver. Whereas the joints previously specified (A16 for the condenser and B16 for the receiver) were practically confined to this apparatus, the B19 join
19、t is very widely used; a condenser from the laboratory stock with a B19 joint can therefore be employed in an emergency if the Dean and Stark condenser is not available. This change will not, however, render obsolete any older apparatus that may still be in use. Investigations have shown that two si
20、zes of condenser are not normally required for the apparatus, and a jacket length of 25 cm. has therefore been standardized in place of the 20 cm. and 30 cm. sizes previously in use. A single size of spray tube is likewise specified, and it is emphasized that this is an optional part of the apparatu
21、s. Additional receivers have been included as developed by the Road Research Laboratory for tests on soils. These are the 25 and 100 ml. receivers with stopcock (each with a plain vapour tube for cork connection). In the 1939 edition the distance which separated the vapour tube from the body of the
22、receiver was fixed at 70 mm. but experience has shown that this may result in the base of the receiver being unduly close to the source of heat under the distillation vessel. It has therefore been decided, for all Type 1 receivers, except the 2 ml. size, to revert to the 150 mm. separation originall
23、y specified in 1936 in BS 614. The Type 2 apparatus of the 1939 edition has been replaced by the modified Dean and Stark type specified by the Institute of Petroleum for the determination of motor fuel diluent in crankcase oil, which may also be used for the determination of water, using a heavier l
24、iquid. As such liquids, e.g. trichlorethylene or perchlorethylene, are generally non-inflammable this apparatus may commend itself in many laboratories owing to the absence of the fire hazard. The 12.5 ml. size is that specified by the Institute of Petroleum and a 3 ml. size has been added for the c
25、onvenience of other users. Little information on assembly of apparatus or on methods of use has been included in this standard as these points are generally dealt with in the test methods which require the use of the apparatus. Licensed Copy: London South Bank University, London South Bank Universit
26、y, Fri Dec 08 13:30:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 756:1952 BSI 03-2000iii The following British Standards make reference to an apparatus of the Dean and Stark type. Consultations have taken place with committees of the Institution which are responsible for the production of these
27、standards, and it is understood that the appropriate size and type of apparatus herein described can be satisfactorily employed in each case, and will be proposed for inclusion in future revisions. Agreement has also been reached with the Institute of Petroleum and the Standardization of Tar Product
28、s Tests Committee to adopt British Standard apparatus for inclusion in future editions of their handbooks on methods of test. BS 76:1943, Tars for road purposes. BS 209:1947, Fuels for oil engines. BS 241:1935, White oil pastes for paints. BS 261:1936, Ready mixed paints (oil gloss). BS 331:1938, Dr
29、iers for paints. BS 390:1938, Oil pastes (excluding white lead, zinc oxide and lithopone) for paints. BS 517:1948, Cresylic acid of specified orthocresol content. BS 521:1948, Cresylic acid of specified metacresol content. BS 523:1948, Phenol. BS 524:1948, Refined cresylic acid. BS 544:1934, Linseed
30、 oil putty. BS 598:1950, Sampling and examination of bituminous road mixtures. BS 618:1935, Emulsions of road tar and of road tar-asphaltic bitumen mixtures for penetration (grouting and semi-grouting) and surface dressing. BS 628-32 and BS 650-56:1950, Vegetable oils. BS 684:1950, Methods of analys
31、is of oils and fats. BS 735:1944, Sampling and analysis of coal and coke for performance and efficiency tests on industrial plant. BS 742:1947, Fuel oils for burners. BS 929:1947, Ready mixed oil paints. BS 1011:1942, Red lead ready mixed paints. BS 1016:1942, Methods for the analysis and testing of
32、 coal and coke. BS 1017:1942, Methods for the sampling of coal and coke. BS 1033:1942, Priming paint (lead base) for the protection of steel sheet. BS 1067:1942, Coal tar pitch felt damp-proof courses for temporary war-time building. BS 1070:1942, Black paint (tar base) for use on iron and steel. BS
33、 1177:1944, Pitch mastic flooring incorporating lake asphalt. BS 1375:1947, Coloured pitch mastic flooring. BS 1450:1948, Black pitch mastic flooring. BS 1469:1948, Coal tar liquid fuels. BS 1673-2, Methods of testing raw rubber and unvulcanized compounded rubber: Methods of chemical analysis. BS 17
34、15:1951, Methods for the analysis of soaps. BS 1737:1951, Jointing materials and compounds for water, town gas and low-pressure steam installations. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:30:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 756:1952 i
35、v BSI 03-2000 BS 434:1952, “Bitumen road emulsion for penetration (grouting and semi-grouting) and surface dressing”, also specifies an apparatus of the Dean and Stark type, but this has a 25 ml. receiver of special design with a longer scale graduated in 01 ml. and has therefore been omitted from t
36、he present standard. SUBSIDIARY STANDARD TEMPERATURE OF 27 C. At the Second Meeting, in 1951, of Technical Committee ISO/TC 48 Laboratory Glassware and Related Apparatus, of the International Organization for Standardization, it was agreed to qualify as follows the acceptance of 20 C. as the standar
37、d temperature for volumetric glassware : “When it is necessary in tropical countries to work at an ambient temperature considerably above 20 C., and these countries do not wish to use exclusively the standard temperature of 20 C., it recommended that they should adopt a temperature of 27 C.” In orde
38、r to meet the requirements of such tropical countries it has been decided to amend the British Standards for volumetric glassware to permit 27 C., as an alternative to 20 C. In the present British Standard this amendment applies to Clause 7 and to the Figure 5 to Figure 12. A British Standard does n
39、ot purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside
40、front cover, pages i to iv, pages 1 to 18, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London
41、 South Bank University, Fri Dec 08 13:30:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 756:1952 BSI 03-20001 1 Scope This British Standard specifies suitable apparatus for the determination of water by the method of distillation with an immiscible liquid. The method is applicable to a wide range
42、of materials in industrial processes and laboratory practice. 2 Assembly of apparatus The apparatus shall consist of the following components, assembled as shown in Figure 1 : a) Distillation vessel. b) Condenser, including spray tube if required. c) Receiver. 3 Material The receiver and condenser s
43、hall be made of borosilicate glass as free as possible from visible defects, and shall be well annealed. 4 Design and dimensions The general design and dimensions of the apparatus shall be as shown in Figure 1 to Figure 12. The only mandatory dimensions are those given in Clause 6 and Table 2. The r
44、emaining dimensions are given for the guidance of manufacturers and are not a mandatory part of the specification, but an apparatus which, on visual inspection, shows any gross departure from them shall be deemed not to comply with the specification. 5 Distillation vessel For different purposes a fl
45、ask made of borosilicate glass or a metal flask or pot is suitable. If a glass flask is used, the connection to the receiver shall be made by means of a cork or by a ground glass joint complying with BS 5721), as specified in Table 1. If a metal vessel is used, the connection shall be made by a cork
46、 or by other suitable means such as that shown in Figure 2. 6 Condenser a) Design and dimensions. The condenser shall be a glass water-cooled reflux type, of the design and dimensions shown in Figure 3. The only mandatory dimensions (see Clause 4) for the condenser are the external diameters of the
47、inner tube and of the jacket, which shall be 1617 mm. and 2325 mm. respectively. b) Construction. In the construction of the condenser, the following points should be noted: i) The joints A and B should be neatly finished as shown in Figure 3; in particular, the bore at B should have the minimum dis
48、turbance. ii) The shoulder above the cone of the B19 joint at C should be elongated as shown in Figure 3, thus avoiding a sharp re-entrant shape which may restrict the free flow of liquid down the inner wall. iii) The cone should be extended beyond the length appropriate to the B19 joint, and the lo
49、wer end ground at an angle of approximately 60 to the axis. The drainage tip should be at the front of the condenser when the lower water-connection is to the left, and the finish should be either smooth or fire-polished. c) Spray tube. The spray tube, if provided, shall be sealed at one end and shall have four small holes spaced regularly round its circumference near the closed end; it shall be of the design illustrated in Figure 4. 7 Receiver a) Type. Two types of receiver are included, as follows: Type 1 is based on