EN 54-7 Fire detection and fire alarm systems — Part 7: Smoke detectors — Point detectors using scattered light, transmitted light or ionization
1 Scope
This European Standard specifies requirements, test methods and performance criteria for point smoke detectors that operate using scattered light, transmitted light or ionization, for use in fire detection and fire alarm systems for buildings (see EN 54-1:1996). # This European Standard includes point smoke detectors that incorporate more than one smoke sensor operating on these principles, and additional requirements and test methods for such detectors are given in Annex N. $
For other types of smoke detector, or smoke detectors working on different principles, this standard should only be used for guidance. Smoke detectors with special characteristics and developed for specific risks are not covered by this standard.
NOTE: Certain types of detector contain radioactive materials. The national requirements for radiation protection differ from country to country and they are not specified in this standard.
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.
3 Terms and definitions
For the purposes of this standard, the following term and definition and those given in EN 54-1:1996 apply: 3.1
response threshold value
aerosol density in the proximity of the specimen at the moment that it generates an alarm signal, when tested as described in 5.1.5
NOTE: The response threshold value may depend on signal processing in the detector and in the control and indicating equipment.
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 as described in clause 5 # and, for detectors with more than one smoke sensor, Annex N $ and shall meet the requirements of the tests.
4.2 Individual alarm indication
Each detector shall be provided with an integral red visual indicator, by which the individual detector, which released an alarm, can be identified until the alarm condition is reset. Where other conditions of the detector can be visually indicated, they shall be clearly distinguishable from the alarm indication, except when the detector is switched into a service mode. For detachable detectors the indicator may be integral with the base or the detector head. The visual indicator shall be visible from a distance of 6 m directly below the detector, in an ambient light intensity up to 500 lux.
4.3 Connection of ancillary devices
Where 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 Monitoring of detachable detectors
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.
4.5 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.
4.6 On-site adjustment of response behaviour
If there is provision for on-site adjustment of the response behaviour of the detector then:
4.7 Protection against the ingress of foreign bodies
The detector shall be so designed that a sphere of diameter (1,3 ± 0,05) mm cannot pass into the sensor chamber(s).
NOTE: This requirement is intended to restrict the access of insects into the sensitive parts of the detector. It is known that this requirement is not sufficient to prevent the access of all insects, however it is considered that extreme restrictions on the size of access holes may introduce the danger of clogging by dust etc. It may therefore be necessary to take other precautions against false alarms due to the entry of small insects.
4.8 Response to slowly developing fires
The provision of “drift compensation” (e.g. to compensate for sensor drift due to the build-up of dirt in the detector), shall not lead to a significant reduction in the detector’s sensitivity to slowly developing fires.
Since it is not practical to make tests with very slow increases in smoke density, an assessment of the detector’s response to slow increases in smoke density shall be made by analysis of the circuit/software, and/or physical tests and simulations.
The detector shall be deemed to meet the requirements of this clause if this assessment shows that:
4.9 Marking
Each detector shall be clearly marked with the following information:
Where any marking on the device uses symbols or abbreviations not in common use then these shall be explained in the data supplied with the device.
The marking shall be visible during installation of the detector and shall be accessible during maintenance. The markings shall not be placed on screws or other easily removable parts.
4.10 Data
Detectors shall either be supplied with sufficient technical, installation and maintenance data to enable their correct installation and operation ‘ or, if all of these data are not supplied with each detector, reference to the appropriate data sheet shall be given on, or with, each detector.
NOTE: Additional information may be required by organizations certifying that detectors produced by a manufacturer conform to the requirements of this standard.
4.11 Additional requirements for software controlled detectors
4.11.1 General
For detectors which rely on software control in order to fulfil the requirements of this standard, the requirements of 4.11.2, 4.11.3 and 4.11.4 shall be met.
4.11.2 Software documentation
4.11.2.1 The manufacturer shall submit documentation which gives an overview of the software design. This documentation shall be in sufficient detail for the design to be inspected for compliance with this standard and shall include at least the following:
4.11.2.2 The manufacturer shall have available detailed design documentation, which only needs to be provided if required by the testing authority. It shall comprise at least the following:
4.11.3 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.
4.11.4 The storage of programs and data
The program necessary to comply with this standard and any pre-set 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.
5 Tests 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 IEC 60068-1:1988+A1:1992 as follows:
5.1.2 Operating conditions for tests
If a test method requires a specimen to be operational, then 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 recognized.
NOTE: The details of the supply and monitoring equipment and the alarm criteria used should be given in the test report.
5.1.3 Mounting arrangements
The specimen shall be mounted by its normal means of attachment in accordance with the manufacturer’s instructions. If these instructions describe more than one method of mounting then the method considered to be most unfavorable 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 60068).
If a requirement or test procedure does not specify a tolerance or deviation limits, then deviation limits of ±5 % shall be applied.
5.1.5 Measurement of response threshold value
The specimen for which the response threshold value is to be measured shall be installed in the smoke tunnel, described in annex A, in its normal operating position, by its normal means of attachment. The orientation of the specimen relative to the direction of airflow shall be the least sensitive orientation, as determined in the directional dependence test, unless otherwise specified in the test procedure.
Before commencing each measurement the smoke tunnel shall be purged to ensure that the tunnel and the specimen are free from the test aerosol.
The air velocity in the proximity of the specimen shall be (0,2 ± 0,04) m s-1 during the measurement, unless otherwise specified in the test procedure.
Unless otherwise specified in the test procedure, the air temperature in the tunnel shall be (23 ± 5) °C and shall not vary by more than 5 K for all the measurements on a particular detector type.
The specimen shall be connected to its supply and monitoring equipment as described in 5.1.2, and shall be allowed to stabilize for a period of at least 15 min, unless otherwise specified by the manufacturer.
5.1.6 Provision for tests
The following shall be provided for testing compliance with this standard:
a) for detachable detectors: twenty detector heads and bases; for non-detachable detectors: twenty specimens;
b) the data required in 4.10.
NOTE 1: Detachable detectors comprise at least two parts; a base (socket) and a head (body). If the specimens are detachable detectors, then the two, or more, parts together are regarded as a complete detector.
The specimens submitted shall be representative of the manufacturer’s normal production with regard to their construction and calibration.
5.2 Repeatability
5.2.1 Object
To show that the detector has stable behaviour with respect to its sensitivity even after a number of alarm conditions.
5.2.2 Test procedure
The response threshold value of the specimen to be tested shall be measured as described in 5.1.5 six times.
The specimen’s orientation relative to the direction of air flow is arbitrary, but it shall be the same for all six measurements.
The maximum response threshold value shall be designated ymax or mmax, the minimum value shall be designated ymin or mmin.
5.2.3 Requirements
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
The lower response threshold value ymin shall be not less than 0,2, or mmin shall not be less than 0,05 dB m-1.
5.3 Directional dependence
5.3.1 Object
To confirm that the sensitivity of the detector is not unduly dependent on the direction of airflow around the detector.
5.3.2 Test procedure
The response threshold value of the specimen to be tested shall be measured eight times as described in 5.1.5, the specimen being rotated 45° about its vertical axis between each measurement, so that the measurements are taken for eight different orientations relative to the direction of air flow.
The maximum response threshold value shall be designated ymax or mmax, the minimum value shall be designated ymin or mmin.
The orientations for which the maximum and minimum response threshold values were measured shall be noted.
In the following tests the orientation for which the maximum response threshold was measured is referred to as the least sensitive orientation, and the orientation for which the minimum response threshold was measured is referred to as the most sensitive orientation.
5.3.3 Requirements
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
The lower response threshold value ymin shall not be less than 0,2, or mmin shall not be less than 0,05 dB m-1.
5.4 Reproducibility
5.4.1 Object
To show that the sensitivity of the detector does not vary unduly from specimen to specimen and to establish response threshold value data for comparison with the response threshold values measured after the environmental tests.
5.4.2 Test procedure
The response threshold value of each of the test specimens shall be measured as described in 5.1.5. The mean of these response threshold values shall be calculated and shall be designated y or m .
The maximum response threshold value shall be designated ymax or mmax; the minimum value shall be designated ymin or mmin.
5.4.3 Requirements
The ratio of the response threshold valuesymax : y or mmax : m shall not be greater than 1,33, and the ratio of the response threshold values y : ymin or m : mmin shall not be greater than 1,5.
The lower response threshold value ymin shall not be less than 0,2, or mmin shall not be less than 0,05 dB m-1.
5.5 Variation in supply parameters
5.5.1 Object
To show that, within the specified range(s) of the supply parameters (e.g. voltage), the sensitivity of the detector is not unduly dependent on these parameters.
5.5.2 Test procedure
The response threshold value of the specimen shall be measured as described in 5.1.5, at the upper and lower limits of the supply parameter (e.g. voltage) range(s) specified by the manufacturer.
The maximum response threshold value shall be designated ymax or mmax and the minimum value shall be designated ymin or mmin.
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
The lower response threshold value ymin shall not be less than 0,2, or mmin shall not be less than 0,05 dB m-1.
5.6 Air movement
5.6.1 Object
To show that the sensitivity of the detector is not unduly affected by the rate of the air flow, and that it is not unduly prone to false alarms in draughts or in short gusts.
5.6.2 Test Procedure
The response threshold value of the specimen to be tested shall be measured as described in 5.1.5 in the most and least sensitive orientations, and shall be appropriately designated y(o,2)max and y(0,2)min or m(0,2)max and m(0,2)min.
These measurements shall then be repeated but with an air velocity, in the proximity of the detector, of (1 ± 0,2) m s-1. The response threshold values in these tests shall be designated y(1,0)max and y(10)min or
m(1,0)max and m(1,0)min.
Additionally, for detectors using ionization, the specimen to be tested shall be subjected, in its most sensitive orientation, to an aerosol-free air flow at a velocity of (5 ± 0,5) m s-1 for a period of not less than 5 min and not more that 7 min, and then at least 10 min later to a gust at a velocity of (10 ± 1) m s-1 for a period of not less than 2 s and not more than 4 s. The specimen shall be monitored during the exposure to aerosol-free air to detect any alarm or fault signals.
5.6.3 Requirements
5.7 Dazzling
5.7.1 Object
To show that the sensitivity of the detector is not unduly influenced by the close proximity of artificial light sources. This test is only applied to detectors using scattered light or transmitted light, as detectors using ionization are considered unlikely to be influenced.
5.7.2 Test procedure
The dazzling apparatus, described in annex D, is installed in the smoke tunnel described in annex A. The specimen is installed in the dazzling apparatus in the least sensitive orientation and connected to its supply and monitoring equipment. The following test procedure is then applied:
The response threshold value is measured as described in 5.1.5.
The four lamps are switched simultaneously ON for 10 s and then OFF for 10 s, ten times.
The four lamps are then switched ON again and after at least 1 min the response threshold value is measured, as described in 5.1.5, with the lamps ON.
The four lamps are then switched OFF.
The above procedure is then repeated but with the detector rotated 90° in one direction (either direction can be chosen), from the least sensitive orientation.
For each orientation, the maximum response threshold value shall be designated mmax and the minimum response threshold value shall be designated mmin.
5.7.3 Requirements
During the periods when the lamps are being switched ON and OFF, and when the lamps are ON before the response threshold value is measured, the specimen shall emit neither an alarm nor a fault signal.
For each orientation, the ratio of the response thresholds mmax : mmin shall not be greater than 1,6.
5.8 Dry heat (operational)
5.8.1 Object
To demonstrate the ability of the detector to function correctly at high ambient temperatures appropriate to the anticipated service environment.
5.8.2 Test procedure
The specimen to be tested shall be installed in the smoke tunnel described in annex A in its least sensitive orientation, with an initial air temperature of (23 ± 5) °C, and shall be connected to its supply and monitoring equipment.
The air temperature in the smoke tunnel shall then be increased to (55 ± 2) °C at a rate not exceeding 1 K min-1, and maintained at this temperature for 2 h.
5.8.3 Requirements
No alarm or fault signal shall be given during the period that the temperature is increasing to the conditioning temperature, or during the conditioning period, until the response threshold value is measured.
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.9 Cold (operational)
5.9.1 Object
To demonstrate the ability of the detector to function correctly at low ambient temperatures appropriate to the anticipated service environment.
5.9.2 Test procedure
5.9.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-1:1990+A1:1993+A2:1994 Test Ab, and as described below.
5.9.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 and shall be connected to supply and monitoring equipment as described in 5.1.2.
5.9.2.3 Conditioning
5.9.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any alarm or fault signals.
5.9.2.5 Final measurements
After a recovery period of at least 1 h at the standard laboratory conditions, the response threshold value sha ll be measured as described in 5.1.5.
5.9.3 Requirements
No alarm or fault signal shall be given during the transition to the conditioning temperature or during the period at the conditioning temperature.
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.10 Damp heat, steady state (operational)
5.10.1 Object
To demonstrate the ability of the detector to function correctly at high relative humidity (without condensation), which may occur for short periods in the anticipated service environment.
5.10.2 Test procedure
5.10.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-56:1988 Test Cb and as described below.
5.10.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 and shall be connected to supply and monitoring equipment as described in 5.1.2.
5.10.2.3 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any alarm or fault signals.
5.10.2.4 Final measurements
After a recovery period of at least 1 h at the standard laboratory conditions, the response threshold value shall be measured as described in 5.1.5.
The greater of the response threshold value measured in this test and that measured for the same specimen in the reproducibility test, shall be designated ymax or mmax, and the lesser shall be designated ymin or mmin.
5.10.3 Requirements
No alarm or fault signal shall be given during the conditioning.
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.11 Damp heat, steady state (endurance)
5.11.1 Object
To demonstrate the ability of the detector to withstand the long-term effects of humidity in the service environment (e.g. changes in electrical properties of materials, chemical reactions involving moisture, galvanic corrosion, etc.).
5.11.2 Test procedure 5.11.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-56:1988 Test Cb or IEC 60068-2-3:1969+A1:1984 Test Ca, and as described below.
11.2.2 State of the specimen during conditioning
Th e specimen shall be mounted as described in 5.1.3 but shall not be supplied with power during the conditioning.
5.11.2.3 Conditioning
5.11.2.4 Final measurements
After a recovery period of at least 1 h in standard laboratory conditions, the response threshold value shall be measured as described in 5.1.5.
5.12 Sulfur dioxide (SO2) corrosion (endurance)
5.12.1 Object
To demonstrate the ability of the detector to withstand the corrosive effects of sulfur dioxide as an atmospheric pollutant.
5.12.2 Test procedure 5.12.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-42:1982 Test Kc, except that the conditioning shall be as described below.
5:.12.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3. It shall not be supplied with power during the conditioning, but it shall have untinned copper wires, of the appropriate diameter, connected to sufficient terminals, to allow the final measurement to be made without making further connections to the specimen.
5.12.2.3 Conditioning
5.12.2.4 Final measurements
Immediately after the conditioning, the specimen shall be subjected to a drying period of 16 h at (40 ± 2) °C, < 50% RH, followed by a recovery period of at least 1 h at the standard laboratory conditions. After this, the response threshold value shall be measured as described in 5.1.5.
The greater of the response threshold value measured in this test and that measured for the same specimen in the reproducibility test, shall be designated ymax or mmax, and the lesser shall be designated ymin or mmin.
5.12.3 Requirements
No fault signal attributable to the endurance conditioning shall be given on reconnection of the specimen. The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.13 Shock (operational)
5.13.1 Object
To demonstrate the immunity of the detector to mechanical shocks, which are likely to occur, albeit infrequently, in the anticipated service environment.
5.13.2 Test procedure
5.13.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-27:1987 Test Ea, except that the conditioning shall be as described below.
5.13.2.2 State of the specimen during conditioning
The specimen shall be mounted as described in 5.1.3 to a rigid fixture, and shall be connected to its supply and monitoring equipment as described in 5.1.2.
5.13.2.3 Conditioning
5.13.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period and for a further 2 min to detect any alarm or fault signals.
5.13.2.5 Final measurements
After the conditioning the response threshold value shall be measured as described in 5.1.5.
The greater of the response threshold value measured in this test and that measured for the same specimen in the reproducibility test shall be designated ymax or mmax, and the lesser shall be designated ymin or mmin.
5.13.3 Requirements
No alarm or fault signal shall be given during the conditioning period or the additional 2 min. The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.14 Impact (operational)
5.14.1 Object
To demonstrate the immunity of the detector to mechanical impacts upon its surface, which it may sustain in the normal service environment, and which it can reasonably be expected to withstand.
5.14.2 Test procedure
5.14.2.1 Apparatus
The test apparatus shall consist of a swinging hammer incorporating a rectangular-section aluminium alloy head (aluminium alloy Al Cu4 Si Mg complying with ISO 209-1:1989, solution treated and precipitation treated condition), with the plane impact face chamfered to an angle of 60° to the horizontal when in the striking position (i.e. when the hammer shaft is vertical). The hammer head shall be (50 ± 2,5) mm high, (76 ± 3,8) mm wide and (80 ± 4) mm long at mid height as shown in Figure E.1. A suitable apparatus is described in annex E.
5.14.2.2 State of the specimen during conditioning
Shock pulse type: Pulse duration: Peak acceleration: Number of directions: Pulses per direction:
The specimen shall be rigidly mounted to the apparatus by its normal mounting means and shall be positioned so that it is struck by the upper half of the impact face when the hammer is in the vertical position (i.e. when the hammer head is moving horizontally). The azimuthal direction and position of impact relative to the specimen shall be chosen as that most likely to impair the normal functioning of the specimen. The specimen shall be connected to its supply and monitoring equipment as described in 5.1.2.
5.14.2.3 Conditioning
5.14.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period and for a further 2 min to detect any alarm or fault signals.
5.14.2.5 Final measurements
After the conditioning the response threshold value shall be measured as described in 5.1.5.
The greater of the response threshold value measured in this test and that measured for the same specimen in the reproducibility test shall be designated ymax or mmax, and the lesser shall be designated ymin or mmin.
5.14.3 Requirements
No alarm or fault signal shall be given during the conditioning period or the additional 2 min. The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.15 Vibration, sinusoidal (operational)
5.15.1 Object
To demonstrate the immunity of the detector to vibration at levels considered appropriate to the normal service environment.
5.15.2 Test procedure
5.15.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-6:1995+Corr.:1995 Test Fc, and as described below.
5.15.2.2 State of the specimen during conditioning
The specimen shall be mounted on a rigid fixture as described in 5.1.3 and shall be connected to its supply and monitoring equipment as described in 5.1.2. The vibration shall be applied in each of three mutually perpendicular axes, in turn. The specimen shall be mounted so that one of the three axes is perpendicular to its normal mounting plane.
5.15.2.4 Measurements during conditioning
The specimen shall be monitored during the conditioning period to detect any alarm or fault signals.
5.15.2.5 Final measurements
The final measurements, as specified in 5.16.2.4, are normally made after the vibration endurance test and only need be made here if the operational test is conducted in isolation.
5.15.3 Requirements
No alarm or fault signal shall be given during the conditioning.
The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.16 Vibration, sinusoidal (endurance)
5.16.1 Object
To demonstrate the ability of the detector to withstand the long-term effects of vibration at levels appropriate to the service environment.
5.16.2 Test procedure
5.16.2.1 Reference
The test apparatus and procedure shall be as described in IEC 60068-2-6:1995+Corr.:1995 Test Fc, and as described below.
5.16.2.2 State of the specimen during conditioning
The specimen shall be mounted on a rigid fixture as described in 5.1.3, but shall not be supplied with power during conditioning. The vibration shall be applied in each of three mutually perpendicular axes, in turn. The specimen shall be mounted so that one of the three axes is perpendicular to its normal mounting axis.
5.16.2.3 Conditioning
The following conditioning shall be applied:
5.16.2.4 Final measurements
After the conditioning the response threshold value shall be measured as described in 5.1.5.
The greater of the response threshold value measured in this test and that measured for the same specimen in the reproducibility test, shall be designated ymax or mmax, and the lesser shall be designated ymin or mmin.
5.16.3 Requirements
No fault signal attributable to the endurance conditioning shall be given on reconnection of the specimen. The ratio of the response threshold values ymax : ymin or mmax : mmin shall not be greater than 1,6.
5.17 Electromagnetic compatibility (EMC), immunity tests (operational)
The following EMC immunity tests shall be carried out, as described in EN 50130-4:1995+A1:1998:
5.18 Fire sensitivity 5.18.1 Object
To show that the detector has adequate sensitivity to a broad spectrum of smoke types as required for general application in fire detection systems for buildings.
5.18.2 Principle
The specimens are mounted in a standard fire test room and are exposed to a series of test fires designed to produce smoke, representative of a wide spectrum of types of smoke and smoke flow conditions.
5.18.3 Test procedure 5.18.3.1 Fire test room
The fire test room shall be equipped with the following measuring instruments arranged as indicated in annex F:
Measuring ionization chamber (MIC). Obscuration meter. Temperature probe.
5.18.3.2 Test Fires
The specimens shall be subjected to the four test fires TF2 to TF5 (see NOTE and annexes G to J). The type, quantity and arrangement of the fuel and the method of ignition are described in annexes G to J for ea ch test fire, along with the end of test condition and the required profile curve limits.
In: order to be a valid test fire, the development of the fire shall be such that the profile curves of m againsty and m against time, fall within the specified limits, up to the time when all of the specimens have generated an alarm signal or the end of test condition is reached, whichever is the earlier. If these conditions are not met then the test is invalid and shall be repeated. It is permissible, and may be necessary, to adjust the quantity, condition (e.g. moisture content) and arrangement of the fuel to obtain valid test fires.
NOTE: The test fire (TF) numbers have been retained from EN 54-9:1982 to avoid confusion.
5.18.3.3 Mounting of the specimens
The four specimens (Nos. 17, 18, 19 and 20) shall be mounted on the fire test room ceiling in the designated area (see annex F). The specimens shall be mounted in accordance with the manufacturer’s instructions, such that they are in the least sensitive orientation, relative to an assumed air flow from the centre of the room to the specimen.
Each specimen shall be connected to its supply and monitoring equipment, as described in 5.1.2, and shall be allowed to stabilize in its quiescent condition before the start of each test fire.
NOTE: Detectors which dynamically modify their sensitivity in response to varying ambient conditions, may require special reset procedures and/or stabilization times. The manufacturer’s guidance should be sought in such cases to ensure that the state of the detectors at the start of each test is representative of their normal quiescent state.
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EN 54-7:2001 5.18.3.4 Initial conditions
Before each test fire the room shall be ventilated with clean air until it is free from smoke, and so that the conditions listed below can be obtained.
NOTE: The stability of the air and temperature affects the smoke flow within the room. This is particularly important for the test fires, which produce low thermal lift for the smoke (e.g. TF2 and TF3). It is therefore recommended that the difference between the temperature near the floor and the ceiling is < 2 K, and that local heat sources that can cause convection currents (e.g. lights and heaters) should be avoided. If it is necessary for people to be in the room at the beginning of a test fire, they should leave as soon as possible, taking care to produce the minimum disturbance to the air.
5.18.3.5 Recording of the fire parameters and response values
During each test fire the following fire parameters shall be recorded continuously or at least once per second.
The alarm signal given by the supply and monitoring equipment shall be taken as the indication that a specimen has responded to the test fire.
The time of response of each specimen shall be recorded along with the fire parameters ya and ma, at the moment of response.
5.18.4 Requirements
All four specimens shall generate an alarm signal, in each test fire, before the specified end of test condition is reached.
Smoke tunnel for response threshold value measurements
The following specifies those properties of the smoke tunnel which are of primary importance for making repeatable and reproducible measurements of response threshold values of smoke detectors. However, since it is not practical to specify and measure all parameters which can influence the measurements, the background information in annex K should be carefully considered and taken into account when a smoke tunnel is designed and used to make measurements in accordance with this standard.
The smoke tunnel shall have a horizontal working section containing a working volume. The working volume is a defined part of the working section where the air temperature and air flow are within the required test conditions. Conformance with this requirement shall be regularly verified under static conditions, by measurements at an adequate number of points distributed within and on the imaginary boundaries of the working volume. The working volume shall be large enough to fully enclose the detector to be tested and the sensing parts of the measuring equipment. The working section shall be designed to allow the dazzling apparatus described in annex D to be inserted. The detector to be tested shall be mounted in its normal operating position on the underside of a flat board aligned with the airflow in the working volume. The board shall be of such dimensions that the edge(s) of the board are at least 20 mm from any part of the detector. The detector mounting arrangement shall not unduly obstruct the air flow between the board and the tunnel ceiling.
Means shall be provided for creating an essentially laminar air flow at the required velocities (i.e. (0,2 ± 0,04) m s-1 or (1,0 ± 0,2) m s-1) through the working volume. It shall be possible to control the temperature at the required values and to increase the temperature at a rate not exceeding 1 K min-1 to 55 °C.
Both aerosol density measurements, m and y, shall be made in the working volume in the proximity of the detector.
M eans shall be provided for the introduction of the test aerosol such that a homogeneous aerosol density is obtained in the working volume.
O nly one detector shall be mounted in the tunnel, unless it has been demonstrated that measurements made simultaneously on more than one detector are in close agreement with measurements made by testing detectors individually. In the event of a dispute the value obtained by individual testing shall be accepted.
Test aerosol for response threshold value measurements
A polydisperse aerosol shall be used as the test aerosol. The maximum of the aerosol mass distribution shall correspond to particle diameters between 0,5 ^m and 1 ^m with the refractive index of the aerosol particles of approximately 1,4.
Smoke measuring instruments
C.1 Obscuration meter
The response threshold of detectors using scattered light or transmitted light is characterized by the absorbance index (extinction module) of the test aerosol, measured in the proximity of the detector, at the moment that it
C.2 Measuring ionization chamber (MIC) C.2.1 General
The response threshold of detectors using ionization is characterized by a non-dimensional quantity y which is derived from the relative change of the current flowing in a measuring ionization chamber, and which is related to the particle concentration of the test aerosol, measured in the proximity of the detector, at the moment that it generates an alarm signal.
C.2.2 Operating method and basic construction
The mechanical construction of the measuring ionization chamber is shown in annex M.
The measuring device consists of a measuring chamber, an electronic amplifier and a method of continuously sucking in a sample of the aerosol or smoke to be measured.
The principle of operation of the measuring ionization chamber is shown in Figure C.1. The measuring chamber contains a measuring volume and a suitable means by which the sampled air is sucked in and passes the measuring volume in such a way that the aerosol/smoke particles diffuse into this volume. This diffusion is such that the flow of ions within the measuring volume is not disturbed by air movements.
The air within the measuring volume is ionized by alpha radiation from an americium radioactive source, such that there is a bipolar flow of ions when an electrical voltage is applied between the electrodes. This flow of ions is affected by the aerosol or smoke particles in a known manner. The relative variation in the current of ions is used as a measurement of the aerosol or smoke concentration.
bearings on a fixed steel shaft mounted in a rigid steel frame, so that the hammer can rotate freely about the axis of the fixed shaft. The design of the rigid frame is such as to allow complete rotation of the hammer assembly when the specimen is not present.
The striker is of dimensions 76 mm wide, 50 mm high and 94 mm long (overall dimensions) and is manufactured from aluminium alloy (Al Cu4 Si Mg to ISO 209-1:1989), solution treated and precipitation treated condition. It has a plane impact face chamfered at (60 ± 1)° to the long axis of the head. The tubular steel shaft has an outside diameter of (25 ± 0,1) mm with walls (1,6 ± 0,1) mm thick.
The striker is mounted on the shaft so that its long axis is at a radial distance of 305 mm from the axis of rotation of the assembly, the two axes being mutually perpendicular. The central boss is 102 mm in outside diameter and 200 mm long and is mounted coaxially on the fixed steel pivot shaft, which is approximately 25 mm in diameter, however the precise diameter of the shaft will depend on the bearings used.
Diametrically opposite the hammer shaft are two steel counter balance arms, each 20 mm in outside diameter and 185 mm long. These arms are screwed into the boss so that a length of 150 mm protrudes. A steel counter balance weight is mounted on the arms so that its position can be adjusted to balance the weight of the striker and arms, as in Figure E.1. On the end of the central boss is mounted a 12 mm wide x 150 mm diameter aluminium alloy pulley and round this an inextensible cable is wound, one end being fixed to the pulley. The other end of the cable supports the operating weight.
The rigid frame also supports the mounting board on which the specimen is mounted by its normal fixings. The mounting board is adjustable vertically so that the upper half of the impact face of the hammer will strike the specimen when the hammer is moving horizontally, as shown in Figure E.1.
To operate the apparatus, the position of the specimen and the mounting board is first adjusted as shown in Figure E.1 and the mounting board is then secured rigidly to the frame. The hammer assembly is then balanced carefully by adjustment of the counter balance weight with the operating weight removed. The hammer arm is then drawn back to the horizontal position ready for release and the operating weight is reinstated. On release of the assembly the operating weight will spin the hammer and arm through an angle of 3n/2 radians to strike the specimen. The mass of the operating weight to produce the required impact energy of 1,9 J equals: