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1、DRAFT FOR DEVELOPMENT DD CEN/TS 14774-3:2004 Solid biofuels Methods for the determination of moisture content Oven dry method Part 3: Moisture in general analysis sample ICS 75.160.10 ? Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Unc
2、ontrolled Copy, (c) BSI DD CEN/TS 14774-3:2004 This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 16 December 2004 BSI 16 December 2004 ISBN 0 580 45019 8 National foreword This Draft for Development is the official English language version
3、 of CEN/TS 14774-3:2004. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature because the Technical Committee needs some time to collect the data in this relatively new area of technology.
4、It should be applied on this provisional basis, so that information and experience of its practical application may be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the European organization responsible for its conversion
5、 to a European standard. A review of this publication will be initiated 2 years after its publication by the European organization so that a decision can be taken on its status at the end of its 3-year life. Notification of the start of the review period will be made in an announcement in the approp
6、riate issue of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into a European standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent in wr
7、iting to the Secretary of BSI Technical Committee PTI/17, Solid biofuels, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an appropriate revision of the text. A list of organizations represented on this
8、 committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using
9、the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. Summary of pages This document comprises a front cover, an inside front cover, the CEN/TS title page, pages 2 to 7 and a back cover. The BSI copyright notice displayed in this document indicates when the document w
10、as last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 14774-3 A
11、ugust 2004 ICS 75.160.10 English version Solid biofuels - Methods for the determination of moisture content - Oven dry method - Part 3: Moisture in general analysis sample Biocombustilbles solides - Dtermination de lhumidit - Mthode par schage ltuve - Partie 3: Humidit de lchantillon pour analyse gn
12、rale Feste Biobrennstoffe - Verfahren zur Bestimmung des Wassergehaltes - Verfahren der Ofentrocknung - Teil 3: Wassergehalt in gewhnlichen Analysenproben This Technical Specification (CEN/TS) was approved by CEN on 19 January 2004 for provisional application. The period of validity of this CEN/TS i
13、s limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN
14、 and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national
15、standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN
16、 COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2004 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 14774-3:2004: E Licensed Co
17、py: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14774-3:2004 (E) 2 Contents Page Foreword3 1 Scope 5 2 Normative references5 3 Terms and definitions .5 4 Principle5 5 Apparatus .5 6 Sample preparation .6 7 Procedur
18、e .6 8 Calculation7 9 Precision.7 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14774-3:2004 (E) 3 Foreword This document (CEN/TS 14774-3:2004) has been prepared by Technical Committee CEN/TC 335 “Soli
19、d Biofuels”, the secretariat of which is held by SIS. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce this CEN Technical Specification : Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, Franc
20、e, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:
21、00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14774-3:2004 (E) 4 Introduction CEN/TS 14774-3:2004 consists of the following parts under the general title Solid Biofuels Methods for the determination of moisture content Oven dry methods. Part 1 Total moisture Reference method Part 2 Total moisture Simpl
22、ified method Part 3 Moisture in general analysis sample Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14774-3:2004 (E) 5 1 Scope This document describes the method of determining the moisture in the an
23、alysis sample by drying the sample in an oven. It is intended to be used for general analysis samples according to prCEN/TS 14780. The method described in this document is applicable to all solid biofuels. NOTE The term moisture content when used with biomass materials can be misleading since untrea
24、ted biomass frequently contains varying amounts of volatile compounds (extractives) which may evaporate when determining the moisture content of the general analyses sample by oven drying. Since biofuels in small particle size are very hygroscopic, their moisture content will vary with change of hum
25、idity of the atmosphere and therefore, the moisture of the analyses sample should always be determined simultaneously when portions are weighed out for other analytical determinations, for example calorific value, carbon, nitrogen. 2 Normative references The following referenced documents are indisp
26、ensable 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. CEN/TS 14588:2003, Solid Biofuels Terminology, definitions and description prCEN/TS 14779, Sol
27、id Biofuels Methods for preparing sampling plans and sampling certificates prCEN/TS 14780, Solid Biofuels - Methods of sample reduction ISO 331, Coal Determination of moisture in the analysis sample Direct gravimetric method 3 Terms and definitions For the purpose of this document, the terms and def
28、initions given in CEN/TS 14588:2003 apply. NOTE In this method the moisture content should be reported on an as analysed basis. 4 Principle The analysis sample of biofuel is dried at a temperature of (105 2) C and the percentage moisture calculated from the loss in mass of the test sample. NOTE The
29、analysis sample can be dried in air atmosphere or in nitrogen atmosphere. If the sample material is susceptible to oxidation (at 105 C), drying in nitrogen atmosphere is to be preferred and detailed in ISO 331. The used drying atmosphere should be reported in accordance with Clause 10. 5 Apparatus 5
30、.1 Drying oven, capable of being controlled (manufacturers specification) at a temperature within the rage of (105 2) C and in which for air the atmosphere changes between 3 and 5 times per hour. The air velocity should be such that the sample particles are not dislodged from their weighing dish. Th
31、e use of nitrogen atmosphere is detailed in ISO 331. 5.2 Weighing dish, of glass or corrosion- and temperature resistant material, with a well fitting lid and of such a size that the sample layer does not exceed 0,2 g/cm2. 5.3 Balance, having sufficient accuracy to weigh the sample within 0,1 mg. Li
32、censed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14774-3:2004 (E) 6 5.4 Dessicator, to avoid absorption of moisture from the atmosphere to the sample. 6 Sample preparation 6.1 The sample used for the determ
33、ination is the general analysis test sample with a particle size of 1 mm or less, prepared according to prCEN/TS 14780. 6.2 Before commencing the determination, mix the analysis sample, preferably by mechanical means. 7 Procedure A minimum of two determinations shall be carried out on the test sampl
34、e. 7.1 Dry an empty weighing dish with its lid at (105 2) C until constant in mass and cool it to room temperature in a dessicator. Note Several dishes can be handled at the same time. 7.2 Weigh the weighing dish with its lid to the nearest 0,1 mg. 7.3 Add minimum 1 g of the analysis sample into the
35、 weighing dish in an even layer and weigh the weighing dish with its lid plus sample to the nearest 0,1 mg. 7.4 Heat the uncovered dish and its lid together with the sample at (105 2) C until constant in mass. Constancy in mass is defined as a change not exceeding 1 mg in mass during a further perio
36、d of heating at (105 2) C over a period of 60 min. The drying time required is normally between 2 3 hours. 7.5 Replace the lid while the dish is still in the oven. Transfer the dish and its contents to a dessicator. Let it cool to room temperature. 7.6 Weigh the dish and its lid with the sample to t
37、he nearest 0,1 mg. Since small particle size biofuels are very hygroscopic its important to weigh rapidly once the sample is cooled. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14774-3:2004 (E) 7 8 C
38、alculation For each determination the moisture content, Mad, in the analysis sample, as analysed, expressed as a percentage by mass, shall be calculated using the following formula: ( m2 m3 ) Mad = _ x 100 (1) ( m2 - m1 ) Where: m1 is the mass in grams of the empty dish plus lid. m2 is the mass in g
39、rams of the dish plus lid plus sample before drying. m3 is the mass in grams of the dish plus lid plus sample after drying. The result for each individual determination shall be calculated to 2 decimal places and for reporting purposes the mean value of the individual results shall be calculated and
40、 rounded to the nearest 0,1 %. 9 Precision 9.1 Repeatability The result of duplicate determinations, carried out in the same laboratory, by the same operator, with the same apparatus on representative portions weighed out at the same time from the analysis sample, shall not differ more than 0,2 % ab
41、solute. 9.2 Reproducibility Because of the varying nature of the solid biofuels covered by this document it is not possible at this time to give a precision statement (reproducibility) for this test method. 10 Test report The test report shall include at least the following information: - identifica
42、tion of the laboratory and the testing date; - identification of the product or sample tested (see prCEN/TS 14779); - a reference to this document; - any deviation from the standard; - the used drying atmosphere; - test result on wet basis; - conditions and observations i.e. unusual features, during
43、 the test procedure, which may affect the result. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:40:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD CEN/TS 14774-3:2004 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the ind
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