EN 54-12:2002

SLOVENSKI STANDARD
01-april-2003
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Fire detection and fire alarm systems - Part 12: Smoke detectors - Line detectors using
an optical light beam
Brandmeldeanlagen - Teil 12: Rauchmelder - Linienförmige Melder nach dem
Durchlichtprinzip
Systemes de détection et d'alarme incendie - Partie 12: Détecteurs de fumée -
Détecteurs linéaires fonctionnant suivant le principe de la transmission d'un faisceau
d'ondes optiques rayonnées
Ta slovenski standard je istoveten z: EN 54-12:2002
ICS:
13.220.20 3RåDUQD]DãþLWD Fire protection
13.320 Alarmni in opozorilni sistemi Alarm and warning systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 54-12
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2002
ICS 13.220.20
English version
Fire detection and fire alarm systems - Part 12: Smoke detectors
- Line detectors using an optical light beam
Systèmes de détection et d'alarme incendie - Partie 12: Brandmeldeanlagen - Teil 12: Rauchmelder -
Détecteurs de fumée - Détecteurs linéaires fonctionnant Linienförmiger Melder nach dem Durchlichtprinzip
suivant le principe de la transmission d'un faisceau d'ondes
optiques rayonnées
This European Standard was approved by CEN on 19 August 2002.
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. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 54-12:2002 E
worldwide for CEN national Members.

Contents
Foreword .5
1 Scope.6
2 Normative references.6
3 Terms and definitions.8
4 Requirements.9
4.1 Compliance.9
4.2 Individual alarm indication.9
4.3 Connection of ancillary devices.9
4.4 Manufacturer’s adjustments .9
4.5 On-site adjustment of response threshold value.9
4.6 Protection against ingress of foreign bodies.9
4.7 Monitoring of detachable detectors and connections.9
4.8 Limit of compensation . 10
4.9 Additional requirements for software controlled detectors .10
4.9.1 General. 10
4.9.2 Software design. 10
4.9.3 The storage of programs and data . 10
4.10 Fault signalling. 10
5 Test methods. 11
5.1 General. 11
5.1.1 Atmospheric conditions for tests . 11
5.1.2 Operating conditions for tests. 11
5.1.3 Mounting arrangements . 11
5.1.4 Tolerances. 11
5.1.5 Measurement of response threshold value.12
5.1.6 Provision for tests. 12
5.1.7 Test schedule . 13
5.2 Reproducibility . 14
5.2.1 Object. 14
5.2.2 Test procedure. 14
5.2.3 Requirements. 14
5.3 Repeatability . 14
5.3.1 Object. 14
5.3.2 Test procedure. 14
5.3.3 Requirements. 14
5.4 Directional dependence . 15
5.4.1 Object. 15
5.4.2 Test procedure. 15
5.4.3 Requirements. 15
5.5 Variation of supply parameters.16
5.5.1 Object. 16
5.5.2 Test procedure. 16
5.5.3 Requirements. 16
5.6 Rapid changes in attenuation.16
5.6.1 Object. 16
5.6.2 Test procedure. 16
5.6.3 Requirements. 16
5.7 Slow changes in attenuation .17
5.7.1 Object. 17
5.7.2 Test procedure. 17
5.7.3 Requirements. 17
5.8 Optical path length dependence.17
5.8.1 Object.17
5.8.2 Test procedure.17
5.8.3 Requirements.17
5.9 Fire sensitivity.18
5.9.1 Object.18
5.9.2 Test procedure.18
5.9.3 Requirements.19
5.10 Stray light.20
5.10.1 Object.20
5.10.2 Test procedure.20
5.10.3 Requirements.20
5.11 Dry heat (operational).21
5.11.1 Object.21
5.11.2 Test procedure.21
5.11.3 Requirements.21
5.12 Cold (operational).22
5.12.1 Object.22
5.12.2 Test procedure.22
5.12.3 Requirements.22
5.13 Damp heat, steady state (operational).23
5.13.1 Object.23
5.13.2 Test procedure.23
5.13.3 Requirements.23
5.14 Damp heat, steady state (endurance).24
5.14.1 Object.24
5.14.2 Test procedure.24
5.14.3 Requirements.24
5.15 Vibration (endurance).25
5.15.1 Object.25
5.15.2 Test procedure.25
5.15.3 Requirements.25
5.16 Electromagnetic compatibility (EMC), immunity tests (operational).26
5.17 Sulphur dioxide SO corrosion (endurance).27
5.17.1 Object.27
5.17.2 Test procedure.27
5.17.3 Requirements.27
5.18 Impact (operational) .28
5.18.1 Object.28
5.18.2 Test procedure.28
5.18.3 Requirements.28
6 Marking and data.29
6.1 Marking.29
6.2 Documentation.29
6.2.1 General .29
6.2.2 Software documentation.30
Annex A (normative) Bench for response threshold value measurements.31
A.1 Technical characteristics of the attenuators.31
A.2 Measuring bench.31
Annex B (normative) Fire test room.32
Annex C (normative)  Smouldering pyrolysis wood fire (TF2).34
C.1 Fuel.34
C.2 Hotplate.34
C.3 Arrangement.34
C.4 Heating rate.35
C.5 End of test condition.35
C.6 Test validity criteria.35
Annex D (normative) Glowing smouldering cotton fire (TF3) .37
D.1 Fuel.37
D.2 Arrangement .37
D.3 Ignition .38
D.4 End of test condition.38
D.5 Test validity criteria.38
Annex E (normative) Flaming plastics (polyurethane) fire (TF4).39
E.1 Fuel.39
E.2 Arrangement .39
E.3 Ignition .39
E.4 End of test condition.39
E.5 Test validity criteria.40
Annex F (normative) Flaming liquid (n-heptane) fire (TF5) .41
F.1 Fuel.41
F.2 Arrangement .41
F.3 Ignition .41
F.4 End of test condition.41
F.5 Test validity criteria.41
Annex G (normative) Apparatus for stray light.43
G.1 Installation.43
G.2 The light source.45
Annex ZA (informative) Clauses of this European Standard addressing essential requirements or
other provisions of EU Directives .46
Bibliography .52
Foreword
This document EN 54-12:2002 has been prepared by Technical Committee CEN/TC 72 “Fire detection and fire
alarm systems”, the secretariat of which is held by BSI.
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 May 2003, and conflicting national standards shall be withdrawn at the latest by
November 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 this document.
This standard has been prepared in cooperation with the CEA (Comité Européen des Assurances) and with
EURALARM (Association of European Manufacturers of Fire and Intruder Alarm Systems).
Information on the relationship between this European Standard and other standards of the EN 54 series is given in
annex A of EN 54-1:1996.
In this European Standard the annexes A to G are normative.
This document includes a Bibliography.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard : Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
1 Scope
This European Standard specifies requirements, test methods and performance criteria for line smoke detectors
utilising the attenuation and/or changes in attenuation of an optical beam, for use in fire detection systems installed
in buildings.
This European Standard does not cover:
 Line smoke detectors designed to operate with separations between opposed components of less than 1 m;

 Line smoke detectors whose optical path length is defined or adjusted by an integral mechanical connection;

Line smoke detectors with special characteristics, which cannot be assessed by the test methods in this European
Standard.
NOTE The term "optical" is used to describe that part of the electromagnetic spectrum produced by the transmitter to which the
receiver is responsive; this is not restricted to visible wavelengths.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN 54-1 1996 Fire detection and fire alarm systems - Part 1: Introduction.
EN 54-7 Fire detection and fire alarm systems - Part 7: Smoke detectors - Point
detectors using scattered light, transmitted light or ionization.
EN 50130-4 1995 Alarm systems - Part 4: Electromagnetic compatibility - Product family
standard: Immunity requirements for components of fire, intruder and social
alarm systems.
EN 60064 Tungsten filament lamps for domestic and similar general lighting purposes.
Performance requirements (IEC 60064:1993, modified).
EN 60068-1 Environmental testing - Part 1: General and guidance (IEC 60068-1:1988 +
Corrigendum 1988 + A1:1992).
EN 60068-2-1 1993 Environmental testing - Part 2: Tests - Test A: Cold (IEC 60068-2-1:1990).
EN 60068-2-2 1993 Basic environmental testing procedures - Part 2: Tests - Test B: dry heat
(IEC 60068-2-2:1974 + IEC 68-2-2A:1976).
EN 60068-2-6 1995 Environmental testing – Part 2: Tests - Test Fc: Vibration, (sinusoidal) (IEC
60068-2-6:1995 + Corrigendum 1995).
EN 60068-2-75 Environmental testing - Part 2: Tests – Test Eh: Hammer tests (IEC 60068-2-
75:1997).
EN 60081 Double-capped fluorescent lamps – Performance specifications (IEC
60081:1997).
HD 323.2.3 S2 Basic environmental testing procedures - Part 2: tests; test Ca: damp heat,
steady state.
HD 323.2.56 S1 1990 Basic environmental testing procedures - Part 2: Tests - Test Cb: Damp heat,
steady state, primarily for equipment.
IEC 60068-2-42 1982 Basic environmental testing procedures - Part 2: Tests - Test Kc: Sulphur
dioxide test for contacts and connections.
3 Terms and definitions
For the purposes of this European Standard the terms and definitions given in EN 54-1:1996 and the following
apply.
3.1
line smoke detector using an optical beam
detector consisting at least of a transmitter and a receiver and which may include reflector(s) for the detection of
smoke by the attenuation and/or changes in attenuation of an optical beam
3.2
transmitter
component from which the optical beam emanates
3.3
receiver
component which receives the optical beam
3.4
optical path length
total distance traversed by the optical beam between the transmitter and the receiver
3.5
opposed component
component [transmitter and receiver or transmitter-receiver and reflector(s)] of the beam detector whose position
determines the optical path
3.6
separation
physical distance between the opposed components [transmitter and receiver or transmitter-receiver and
reflector(s)]
3.7
attenuation
value "C", expressed in dB, of the reduction in intensity of the optical beam at the receiver, defined by the following
equation:
C = 10 log (I /I)
10 0
where
I is the received intensity without reduction in intensity;
I is the received intensity after reduction in intensity.
3.8
response threshold value
value of attenuation at the moment an alarm signal is generated by a specimen, when tested in accordance with
5.1.5
3.9
sensitivity adjustment
any adjustment during or after commissioning which leads to a change in the response to fire
4 Requirements
4.1 Compliance
In order to comply with this standard the detector shall meet the requirements of this clause, which shall be verified
by visual inspection or engineering assessment, shall be tested in accordance with clause 5 and shall meet the
requirements of the tests.
4.2 Individual alarm indication
Each detector shall be provided with an integral red visible indicator, by means of which each individual detector
which releases an alarm can be identified, until the alarm condition is reset.
4.3 Connection of ancillary devices
If the detector provides for connections to ancillary devices (e.g. remote indicators, control relays), open or short-
circuit failures of these connections shall not prevent the correct operation of the detector.
4.4 Manufacturer’s adjustments
It shall not be possible to change the manufacturer's settings except by special means (e.g. the use of a special
code or tool, or by breaking or removing a seal).
4.5 On-site adjustment of response threshold value
If there is provision for on-site adjustment of the response threshold value of the detector then:
a) For each setting, at which the manufacturer claims compliance with this standard, the detector shall comply
with the requirements of this standard, and access to the adjustment means shall only be possible by the use
of a code or special tool or by removing the detector from its base or mounting;
b) any setting(s), at which the manufacturer does not claim compliance with this standard, shall only be
accessible by the use of a code or special tool, and it shall be clearly marked on the detector or in the
associated data, that if these setting(s) are used, the detector does not comply with this standard.
NOTE These adjustments may be carried out at the detector or at the control and indicating equipment, for example.
4.6 Protection against ingress of foreign bodies
The detector shall be designed so that a sphere of diameter (1,3 ± 0,05) mm cannot pass into any enclosure
containing active opto-electronic components, when the detector is in operational condition.
4.7 Monitoring of detachable detectors and connections
For detachable detectors, a means shall be provided for a remote monitoring system (e.g. the control and
indicating equipment) to detect the removal of the head from the base, in order to give a fault signal.
If there are cables connecting separate parts of the detector, then a means shall be provided for a remote
monitoring system (e.g. the control and indicating equipment) to detect a short or open circuit on those cables, in
order to give a fault signal.
4.8 Limit of compensation
The detector shall emit either a fault or alarm signal at the limit of compensation for the effect of a slowly changing
response (signal).
Since it is practically impossible to perform tests with very slight increases in smoke density, an evaluation of the
detector's conformity shall be made by analysing the circuits/software and/or by physical tests and simulations.
4.9 Additional requirements for software controlled detectors
4.9.1 General
For detectors which rely on software control in order to fulfil the requirements of this standard, the requirements of
4.9.2 and 4.9.3 shall be met.
4.9.2 Software design
In order to ensure the reliability of the detector, the following requirements for software design shall apply:
a) the software shall have a modular structure;
b) the design of the interfaces for manually and automatically generated data shall not permit invalid data to cause
error in the program operation;
c) the software shall be designed to avoid the occurrence of deadlock of the program flow.
4.9.3 The storage of programs and data
The program necessary to comply with this standard and any preset data, such as manufacturer's settings, shall be
held in non-volatile memory. Writing to areas of memory containing this program and data shall only be possible by
the use of some special tool or code and shall not be possible during normal operation of the detector.
Site-specific data shall be held in memory which will retain data for at least two weeks without external power to the
detector, unless provision is made for the automatic renewal of such data, following loss of power, within 1 h of
power being restored.
4.10 Fault signalling
A fire alarm signal shall not be cancelled by a fault resulting from a rapid change in obscuration (in accordance with
5.6) or by a result of the limit of compensation being reached (in accordance with 4.8).
5 Test methods
5.1 General
5.1.1 Atmospheric conditions for tests
Unless otherwise stated in a test procedure, the testing shall be carried out after the test specimen has been
allowed to stabilize in the standard atmospheric conditions for testing as described in EN 60068-1 as follows:
 temperature:  15 °C to 35 °C;
 relative humidity: 25 % to 75 %;
 air pressure:  86 kPa to 106 kPa.

NOTE If variations in these parameters have a significant effect on a measurement, then such variations should be kept to
a minimum during a series of measurements carried out as part of one test on one specimen.
5.1.2 Operating conditions for tests
If a test method requires a specimen to be operational, the specimen shall be connected to suitable supply and
monitoring equipment with characteristics as required by the manufacturer's data. Unless otherwise specified in the
test method, the supply parameters applied to the specimen shall be set within the manufacturer's specified
range(s) and shall remain substantially constant throughout the tests. The value chosen for each parameter shall
normally be the nominal value, or the mean of the specified range.
If a test procedure requires a specimen to be monitored to detect any alarm or fault signals, then connections shall
be made to any necessary ancillary devices (e.g. through wiring to an end-of-line device for conventional detectors)
to allow a fault signal to be recognised.
The details of the supply and monitoring equipment and the alarm criteria used shall be given in the test report.
5.1.3 Mounting arrangements
The specimen shall be mounted by its normal means of attachment and aligned in accordance with the
manufacturer's instructions. If these instructions describe more than one method of mounting, the method
considered to be most unfavourable shall be chosen for each test.
5.1.4 Tolerances
Unless otherwise stated, the tolerances for the environmental test parameters shall be as given in the basic
reference standards for the test (e.g. the relevant Part of IEC/EN 60068).
If a requirement or a test procedure does not specify a tolerance or deviation limits, deviation limits of ± 5 % shall
be applied.
5.1.5 Measurement of response threshold value
5.1.5.1 General
The specimen, for which the response threshold value is to be measured, shall be installed on the measuring
bench, conforming to annex A, in its normal operating position, by its normal means of attachment in accordance
with 5.1.3.
The specimen shall be connected to its supply and monitoring equipment in accordance with 5.1.2, and shall be
allowed to stabilize for at least 15 min.
The response threshold value shall be recorded as C.
5.1.5.2 Operating conditions
On a rigid support assemble the receiver at a longitudinal distance of at least 500 mm from the transmitter or the
transmitter - receiver at the same distance from the reflector (see Figure A.1), then place a filter holder as close as
possible to the front of the receiver, adjusting the filter holder so that the whole beam passes through the filter. This
filter holder shall be used to mount the filters used during the measurement of response threshold value.
The height h separating the axis of the optical beam above the support shall be 10 times the diameter (or the
vertical dimension) of the optical system of the receiver.
Adjustment for path length or alignment, if required, shall be carried out in accordance with the manufacturer's
instructions.
Unless otherwise stated in a test procedure, the response threshold value shall be measured with a simulated
maximum separation carried out using means agreed by the manufacturer.
5.1.5.3 Measurements
The response threshold value is determined by the value of the lowest value test filter required to give an alarm
within 30 s after introduction in the beam. The minimum resolution for optical density filters shall be in accordance
with Table A.1 (see annex A).
5.1.6 Provision for tests
The following shall be provided for testing compliance with this standard:
a) seven detectors;
b) the documentation required in 6.2.
The specimens submitted shall be representative of the manufacturer's normal production with regard to their
construction and calibration.
NOTE This implies that the mean response threshold value of the seven specimens, found in the reproducibility test should
also represent the production mean, and that the limits specified in the reproducibility test should also be applicable to the
manufacturer's production.
5.1.7 Test schedule
The specimens shall be tested in accordance with the test schedule in Table 1. After the reproducibility test, the
two least sensitive specimens (i.e. those with the highest response thresholds) shall be numbered 6 and 7, and the
others shall be numbered 1 to 5.
Table 1 — Test Schedule
Test Clause Specimen N°(s)
Reproducibility 5.2 all specimens
Repeatability 5.3 2
Directional dependence 5.4 1
Variation of supply parameters 5.5 1
Rapid changes in obscuration 5.6 1
Slow changes in obscuration 5.7 1
Optical path length dependence 5.8 1
Fire sensitivity 5.9 6 and 7
Stray light 5.10 6
Dry heat (operational) 5.11 3
Cold (operational) 5.12 3
Damp heat, steady state (operational) 5.13 2
Damp heat, steady state (endurance) 5.14 2
Vibration (endurance) 5.15 7
a
Electrostatic discharge (operational) 5.16 4
a
Radiated electromagnetic fields (operational) 5.16 6
a
Conducted disturbances induced by electromagnetic fields 5.16 6
(operational)
a
Fast transient bursts (operational) 5.16 4
a
Slow high energy voltage surges (operational) 5.16 6
Sulphur dioxide SO corrosion (endurance) 5.17 5
Impact (operational) 5.18 1
a
In the interests of test economy, it is permitted to use the same specimen for more than one EMC test.
In that case, intermediate functional test(s) on the specimen(s) used for more than one test may be
deleted, and the functional test conducted at the end of the sequence of tests. However it should be
noted that in the event of a failure, it may not be possible to identify which test exposure caused the
failure (see clause 4 of EN 50130-4:1995).
5.2 Reproducibility
5.2.1 Object
The detector is tested to show that the sensitivity does not vary unduly from specimen to specimen.
5.2.2 Test procedure
Adjust the specimens to the maximum sensitivity.
Measure the response threshold value of each of the specimens in accordance with 5.1.5.
The mean of these response threshold values shall be calculated and shall be designated C
rep.
The maximum response threshold value shall be designated C and the minimum value shall be designated
max
C .
min
5.2.3 Requirements
C shall not be less than 0,4 dB.
min
The ratio of the response threshold values C : C shall not be greater than 1,33, and the ratio of the response
max rep
threshold values C : C shall not be greater than 1,5.
rep min
5.3 Repeatability
5.3.1 Object
The detector is tested to show that it has stable behaviour with respect to its sensitivity even after a number of
alarm conditions.
5.3.2 Test procedure
Adjust the specimen to the maximum sensitivity.
Measure the response threshold value of the specimen three times in accordance with 5.1.5.
The period between successive determinations shall not be less than 15 min or more than 1 h.
The specimen is then powered without interruption or disturbance to the optical beam for 7 days. Again measure
the response threshold value of the specimen in accordance with 5.1.5, once.
The maximum response threshold value shall be designated C and the minimum value shall be designated
max
C .
min
5.3.3 Requirements
No alarm or fault signals shall be emitted during the 7 days between testing.
C shall not be less than 0,4 dB.
min
The ratio of the response threshold values C : C shall not be greater than 1,6.
max min
5.4 Directional dependence
5.4.1 Object
The detector is tested to show that small angular inaccuracies in alignment (within the maximum stated by the
manufacturer), resulting from installation and/or movement in the structure of a building do not affect the operation
of the detector.
5.4.2 Test procedure
5.4.2.1 State of the specimen during conditioning
Adjust the specimen to the maximum sensitivity, and mount in accordance with 5.1.3 with the maximum separation.
Connect in accordance with 5.1.2.
With the agreement of the manufacturer this test may be carried out outside of the limits of atmospheric conditions
of 5.1.1.
5.4.2.2 Conditioning
Subject each opposed component to the following procedures whilst holding the other component stationary.
-1
a) Rotate the component in a clockwise direction about a vertical axis at a rate of (0,3 ± 0,05)° min up to the
maximum angular misalignment declared by the manufacturer in accordance with 6.2. After 2 min in this
position, place an attenuator of value 6 dB in the optical path.
Remove the attenuator and reset the detector.
Return the rotated component to its original position, reset the detector and allow it to stabilize;
b) Repeat the procedure described in a) but rotate the component in a counter-clockwise direction;
c) Repeat the procedures described in a) and b) but rotate the component about a horizontal axis normal to the
beam.
5.4.3 Requirements
The specimen shall not emit a fault or an alarm signal whilst being rotated in the directions specified within the
angular tolerances stated by the manufacturer (see 6.2a)).
The specimen shall emit an alarm signal no more than 30 s after the total introduction of the attenuator specified in
5.4.2.2.
5.5 Variation of supply parameters
5.5.1 Object
The detector is tested to show that, within the specified range(s) of the supply parameters (e.g. voltage), its
sensitivity is not unduly dependent on these parameters.
5.5.2 Test procedure
Adjust the specimen to the maximum sensitivity.
Measure the response threshold value of the specimen in accordance with 5.1.5 under the extremes of the
specified conditions (e.g. minimum and maximum voltage).
The maximum response threshold value shall be designated C and the minimum value shall be designated
max
C .
min
NOTE For conventional detectors the supply parameter is the dc voltage applied to the detector. For other types of
detector (e.g. analogue addressable) signal levels and timing may need to be considered. If necessary the manufacturer may be
requested to provide suitable supply equipment to allow the supply parameters to be changed as required.
5.5.3 Requirements
C shall not be less than 0,4 dB.
min
The ratio of the response threshold values C : C shall not be greater than 1,6.
max min
5.6 Rapid changes in attenuation
5.6.1 Object
The detector is tested to ensure that it will produce alarm or fault signals, within an acceptable time, after a sudden
large sustained increase in beam attenuation.
5.6.2 Test procedure
Adjust the specimen to the minimum sensitivity, and mount and connect in accordance with 5.1.5.
The following attenuators shall be used:
 attenuator A: value 6 dB;
+3
 attenuator B: value 10 dB.
Place the attenuator A in the optical path. The time to reach maximum obscuration shall not be greater than 1 s.
Keep the attenuator A in place for 40 s.
Remove attenuator A, reset the detector and place the attenuator B in the optical path. The time to reach maximum
obscuration shall not be greater than 1 s. Keep the attenuator B in place for 70 s
5.6.3 Requirements
The specimen shall emit an alarm signal no more than 30 s after the total introduction of the attenuator A between
the components.
The specimen shall emit a fault or alarm signal no more than 60 s after the total introduction of the attenuator B
between the components.
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