1、BRITISH STANDARD BS EN 13938-2:2004 Explosives for civil uses Propellants and rocket propellants Part 2: Determination of resistance to electrostatic energy The European Standard EN 13938-2:2004 has the status of a British Standard ICS 71.100.30 BS EN 13938-2:2004 This British Standard was published
2、 under the authority of the Standards Policy and Strategy Committee on 4 November 2004 BSI 4 November 2004 ISBN 0 580 44727 8 National foreword This British Standard is the official English language version of EN 13938-2:2004. The UK participation in its preparation was entrusted to Technical Commit
3、tee CII/61, Explosives for civil uses, which has the responsibility to: A list of organizations represented on this 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
4、 found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are
5、responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and k
6、eep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 15 and a back cover. The BSI copyright notice displayed in this document
7、indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN139382 October2004 ICS71.100.30 Englishversion ExplosivesforcivilusesPropellantsandrocketpropellants Part2:Determinationofresistancetoelectrostatice
8、nergy ExplosifusagecivilPoudrepropulsiveetpropergolpour fusePartie2:Dterminationdelarsistancelnergie lectrostatique ExplosivstoffefrzivileZweckeTreibladungspulverund RaketentreibstoffeTeil2:Bestimmungder WiderstandsfhigkeitgegenelektrostatischeEnergie ThisEuropeanStandardwasapprovedbyCENon23August20
9、04. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatort
10、oanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodieso
11、fAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORM
12、ALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN139382:2004:EEN 13938-2:2004 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and defini
13、tions4 4 Apparatus .4 5 Preparation of test sample5 6 Procedure .5 7 Test report 5 Annex A (informative) Range of applicability of the test method.8 Annex B (normative) Sieving method9 Annex C (normative) Calibrating procedure for electrostatic discharge generator .10 C.1 General10 C.2 Device to be
14、tested 10 C.3 Apparatus .10 C.4 Procedure .11 C.4.1 Voltage and capacitor calibration 11 C.4.2 Discharge circuit calibration 11 C.4.3 Additional calibration in case of an additional series resistance.12 C.5 Requirements for the generator .13 Annex D (normative) Screening method for electrostatic dis
15、charge generator .14 D.1 Material .14 D.2 Procedure .14 Annex ZA (informative) Clauses of this European Standard addressing essential requirements or other provisions of EU Directives. .15 EN 13938-2:2004 (E) 3 Foreword This document (EN 13938-2) has been prepared by Technical Committee CEN/TC 321 “
16、Explosives for Civil Uses“, the secretariat of which is held by AENOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2005, and conflicting national standards shall be withdrawn at the late
17、st by April 2005. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative annex ZA, which is an integral part of thi
18、s document. This European Standard is one of a series of standards with the generic title Explosives for civil uses - Propellants and Rocket Propellants. The other parts of this series are listed below: EN13938-1 Part 1: Requirements. EN13938-3 Part 3: Determination of deflagration to detonation tra
19、nsition. EN13938-4 Part 4: Determination of burning rate under ambient conditions. EN13938-5 Part 5: Solid rocket propellants. Determination of voids and fissures EN13938-6 Part 6: Solid rocket propellants. Guide for the determination of integrity of inhibitor coatings. EN13938-7 Part 7: Determinati
20、on of properties of black powder. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, I
21、celand, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 13938-2:2004 (E) 4 1 Scope This document specifies a method for the determination of resistance to electrostatic energy for prope
22、llants containing a mass fraction of at least 5 % of particles which pass through a 1 mm sieve. This method does not apply to black powder. NOTE: If the mass fraction of particles smaller than 1 mm size is less than 5 % the propellant is considered to be insensitive to electrostatic energy and this
23、test is not performed. 2 Normative references The following referenced documents are indispensable 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 EN 1
24、3857-1:2003, Explosives for civil uses Part 1: Terminology. EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025:1999). ISO 565, Test sieves; Metal wire cloth, perforated metal plate and electroformed sheet - Nominal sizes of openings 3 Ter
25、ms and definitions For the purposes of this document, the terms and definitions given in EN 13857-1:2003 and the following apply. 3.1 reaction occurrence of report, crackling, sparkling and/or flame 3.2 partial reaction change of colour, opening of the cell or heat traces at the surface of the cell
26、4 Apparatus 4.1 Cells and covers (see Figure 1). The cell consists of: a plastics disc, e.g. polyvinylchloride, thickness (3,0 0,1) mm, diameter (32 1) mm, with a centred drilled hole, diameter (6,3 0,1) mm; a copper disc, thickness approximately 1 mm, diameter (19 1) mm, which forms the cell base.
27、The plastics disc is fixed to the copper disc by means of a bead of adhesive around the outer edge. The cover consists of a copper disc, thickness approximately 0,1 mm, diameter (16 1) mm which is fixed to the upper part of the plastics disc by means of a double-sided adhesive tape. EN 13938-2:2004
28、(E) 5 4.2 Electrostatic energy supply (see Figure 2) The electrostatic energy supply consists of: generator capable of applying a 10 kV continuous voltage; three capacitors: capacitance 0,001 F, 0,01 F and 0,1 F, each with a relative tolerance of 10 %; coaxial cable, length 1,85 m, characteristic im
29、pedance 50 , capacitance 100 pF/m, attenuation 95 10 -3dB/m at 200 MHz; two brass electrodes. and, if necessary: selector switch; change-over relay (in vacuum). 5 Preparation of test sample Take a 100 g sample and sieve it according to the sieving method given in annex B. The fraction which passes t
30、hrough the 1,0 mm sieve shall be used for the test, when this fraction is greater than or equal to 5 g. If not, the test shall not be performed. The test sample shall be conditioned at (20 5) C and (60 10) % relative humidity for 24 h. 6 Procedure Calibrate the generator according to the procedure g
31、iven in annex C. Alternatively, the screening procedure described in annex D can be used. Fill the cell, i.e. the hole in the plastics disc, with a portion of the test sample, ensuring that the cover will be in contact with the propellant and without tamping. Close the cell with the cover, using dou
32、ble-sided adhesive tape, and maintain it at (20 5) C and (30 10) % relative humidity. Place the cell onto the lower electrode. Then bring the upper electrode in contact with the cover of the cell. Select a capacitor and charge it by applying the 10 kV voltage. Then discharge the capacitor through th
33、e electrodes. During testing and when recovering the remainder of the test portion, observe whether reaction or partial reaction occurs, i.e. a positive event. Carry out a series of test runs by using a new cell for each run. Start with a 5 J energy level (capacitance 0,1 F). Test 20 test portions w
34、ith the 5 J energy level. If a reaction or partial reaction occurs stop the test and proceed with a 0,5 J energy level (capacitance 0,01 F) for the next 20 runs. If there is a reaction or partial reaction continue with a 0,05 J energy level (capacitance 0,001 F) for another 20 runs unless a reaction
35、 or partial reaction occurs. Report the test result as the limiting energy, i.e. the maximum energy level without reaction or partial reaction in a series of 20 runs. For example: if a reaction or partial reaction is obtained at the 0,05 J energy level, express the limiting energy as 0.05 J. 7 Test
36、report The test report shall conform to EN ISO/IEC 17025. In addition the following information shall be given: a) reference to this standard; b) complete identification of the substance under test, including grain size distribution; c) individual test results, as: no reaction, partial reaction or r
37、eaction; d) limiting energy. EN 13938-2:2004 (E) 6 Dimensions in millimetres Key 1 Upper copper disc 2 Plastics disc 3 Lower copper disc 4 Substance under test 5 Adhesive bead 6 Upper copper disc (cover) 7 Plastics disc 8 Lower copper disc (base) 9 Double-sided adhesive tape Figure 1 - Cell and cove
38、r EN 13938-2:2004 (E) 7 Key 1 Generator 2 Electrodes 3 Cell and cover 4 Selector switch 5 Coaxial cable 6 Discharge switch Figure 2 - Electrostatic energy supply EN 13938-2:2004 (E) 8 Annex A (informative) Range of applicability of the test method Range of applicability of the test method: - 30 C to
39、 + 80 C. EN 13938-2:2004 (E) 9 Annex B (normative) Sieving method The method uses sieves according to ISO 565 and a sieving machine, e.g. “Fritsch analysette 3“. The aperture sizes of the sieves are given in Table B.1. Table B.1 Aperture size of the sieves Number n 1 2 3 4 5 6 7 8 Aperture size (mm)
40、 X n0,10 0,16 0,25 0,40 0,63 1,0 1,6 2,5 The sieves, cover lid and lower collection bin are made of stainless steel. Take 1 000 g (M) of the sample. Place the sieves on top of the collection bin in the order of the indicated numbers. Put the sample in the top sieve and close the column of sieves wit
41、h the cover lid. Operate the sieving machine for 15 min. Weigh the different fractions, m 1is the amount of sample passing through sieve number 1, m 2is the amount of sample passing through sieve number 2 and retained on sieve number 1, etc. The different percentages are calculated according to: P 1
42、= 100 m 1 /M P 2= 100 (m 1 +m 2 )/M P 8= 100 (m 1 +m 2 +m 8 )/M and the balance: B = 100 (m 1 +m 2 +m 8 +m 9 )/M The amplitude of the sieving machine is adjusted, if the machine has this option, to a medium level, e.g. “5” for the Fritsch apparatus. EN 13938-2:2004 (E) 10 Annex C (normative) Calibra
43、ting procedure for electrostatic discharge generator C.1 General This annex describes the procedure to be used to calibrate the generator ; this calibration is necessary to ensure that the generator used will provide consistent results from one testing place to another. C.2 Device to be tested Only
44、the discharge circuit of the generator is calibrated, including cables which are used to connect the testing cell. If the generator includes an optional serial resistance, R o(for example: 330 additional resistance to simulate the “human body discharge“), the calibration shall be performed without t
45、he optional resistance (C.4.1 and C.4.2); then a supplementary calibration procedure as described in C.4.3 shall be carried out. C.3 Apparatus - High Voltage probe with a calibrated high input impedance (usually approximately 1 G ) Calibration of the input impedance may be obtained by simple measure
46、ment with a Ohmmeter; voltage at which the measurement is made shall be chosen as high as possible (approximately 1 kV for example) - Current probe (using inductive effect) With a transfer function of 0,1 V/A - Oscilloscope Band width 20 MHz EN 13938-2:2004 (E) 11 C.4 Procedure C.4.1 Voltage and cap
47、acitor calibration a) Connect the output of the generator on the High Voltage probe. b) Set the generator at the highest voltage intended to be used for the testing. c) Discharge the generator in the same manner as used for testing a sample. d) Record the voltage versus time. The curve should be hig
48、hly damped (exponential decrease). e) Determinate U max. f) Calculate the time constant = RC using the following equation: = (t 2 t 1) Ln U U 2 1where, U iis voltage and t i is time at the point i of the exponential discharge curve. Preferably choose points 1 and 2 respectively as 10 % and 90 % of U maxfor calculation. g) Calculate C (capacitance of the discharge circuit) from and R (resistance of the discharge circuit impedance of the high voltage probe).
