FprEN 13938-2

SLOVENSKI STANDARD
01-april-2021
Eksplozivi za civilno uporabo - Smodniki in raketna goriva - 2. del: Ugotavljanje
odpornosti proti elektrostatični energiji
Explosives for civil uses - Propellants and rocket propellants - Part 2: Determination of
resistance to electrostatic energy
Explosivstoffe für zivile Zwecke - Treibladungspulver und Raketentreibstoffe - Teil 2:
Bestimmung der Widerstandsfähigkeit gegen elektrostatische Energie
Explosifs à usage civil - Poudres propulsives et propergols pour fusées - Partie 2 :
Détermination de la résistance à l'énergie électrostatique
Ta slovenski standard je istoveten z: prEN 13938-2
ICS:
71.100.30 Eksplozivi. Pirotehnika in Explosives. Pyrotechnics and
ognjemeti fireworks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 13938-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2021
ICS 71.100.30 Will supersede EN 13938-2:2004
English Version
Explosives for civil uses - Propellants and rocket
propellants - Part 2: Determination of resistance to
electrostatic discharge
Explosifs à usage civil - Poudres propulsives et Explosivstoffe für zivile Zwecke - Treibladungspulver
propergols pour fusées - Partie 2 : Détermination de la und Raketentreibstoffe - Teil 2: Bestimmung der
résistance à l'énergie électrostatique Widerstandsfähigkeit gegen elektrostatische Energie
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 321.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13938-2:2021 E
worldwide for CEN national Members.

prEN 13938-2:2021 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Apparatus . 4
6 Preparation of test sample . 7
7 Procedure . 7
8 Test report . 7
Annex A (normative) Sieving method . 8
Annex B (informative) Calibrating procedure for electrostatic discharge generator . 9
B.1 General. 9
B.2 Device to be tested . 9
B.3 Apparatus . 9
B.3.1 High Voltage probe with a calibrated high input impedance. . 9
B.3.2 Current probe or shunt . 9
B.3.3 Oscilloscope. Band width ≥ 100 MHz. For digital oscilloscope with a sampling at least
of 20 MS/s. . 9
B.4 Procedure . 9
B.4.1 Voltage and capacitor calibration . 9
B.4.2 Discharge circuit calibration . 10
B.4.3 Additional calibration in case of an additional series resistance . 11
B.5 Requirements for the generator. 11
Annex C (informative) Screening method for electrostatic discharge generator . 12
C.1 Material . 12
C.2 Procedure . 12
Annex ZA (informative) Relationship between this European Standard and the essential
safety requirements of Directive 2014/28/EU relating to the making available on the
market and supervision of explosives for civil uses aimed to be covered . 13
Bibliography . 14

prEN 13938-2:2021 (E)
European foreword
This document (prEN 13938-2:2021) has been prepared by Technical Committee CEN/TC 321
“Explosives for civil uses”, the secretariat of which is held by UNE.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13938-2:2004.
In comparison with the previous edition, the following technical modifications have been made:
a) the normative references have been updated;
b) Clause 4, Principle, has been added;
c) Annex A, Range of applicability of the test method, has been removed;
d) Annex ZA has been updated.
This document has been prepared under a Standardization Request (M/562) annexed to the Commission
Implementing Decision C(2019)6634 final as regards Explosives for civil uses given to CEN by the
European Commission and the European Free Trade Association, and supports Essential Safety
requirements of Directive 2014/28/EU.
For relationship with Directive 2014/28/EU, see informative Annex ZA, which is an integral part of this
document.
EN 13938, Explosives for civil uses — Propellants and rocket propellants, is currently composed of the
following parts:
— Part 1: Requirements
— Part 2: Determination of resistance to electrostatic discharge
— Part 3: Determination of deflagration to detonation transition
— Part 4: Determination of burning rate under ambient conditions
— Part 5: Determination of voids and fissures
— Part 6: Solid rocket propellants — Guide for the determination of integrity of inhibitor coatings
— Part 7: Determination of safe and reliable ignition and complete deflagration of black powder
prEN 13938-2:2021 (E)
1 Scope
This document specifies a method for the determination of resistance to electrostatic energy for
propellants 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 test is not performed.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
prEN 13857-1:2021, Explosives for civil uses — Part 1: Terminology
ISO 565:1990, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal
sizes of openings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in prEN 13857-1:2021 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
4 Principle
Sudden and momentary electric current that flows in a sample at an electrical potential. During the
handling operation, the particles could charge and an electrostatic discharge might occur, posing a risk
of fire and explosion an also for people.
5 Apparatus
5.1 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.
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.
prEN 13938-2:2021 (E)
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 cover
prEN 13938-2:2021 (E)
5.2 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 µF, 0,01 µF and 0,1 µF, each with a relative tolerance of ±10 %;
— coaxial cable, length 1,85 m, characteristic impedance 50 Ω, capacitance 100 pF/m, attenuation
−3
95 × 10 dB/m at 200 MHz;
— two brass electrodes;
and, if necessary:
— selector switch;
— change-over relay (in vacuum).

Key
1 generator
2 electrodes
3 cell and cover
4 selector switch
5 coaxial cable
6 discharge switch
Figure 2 — Electrostatic energy supply
5.3 Sieves. The sieves shall comply with Annex A.
5.4 Conditioning chamber for maintaining a temperature of (20 ± 5) °C and a relative humidity of not
greater than (60 ± 10) %.
5.5 Balance capable of determining the sample weight to ±0,1 g.
prEN 13938-2:2021 (E)
6 Preparation of test sample
Take a 100 g sample and sieve it according to the sieving method given in Annex A. The fraction which
passes through 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.
7 Procedure
Calibrate the generator according to the procedure given in Annex B. Alternatively, the screening
procedure described in Annex C 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 double-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
the 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 µF). Test 20 test portions with 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 µF) for the next 20 runs. If there is a reaction or
partial reaction continue with a 0,05 J energy level (capacitance 0,001 µF) for another 20 runs unless a
reaction or partial reaction occurs.
Report the test result as the limiting energy, i.e. the
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