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Tiêu đề Respiratory Protective Devices for Self-Rescue - Filtering Devices with Hood for Escape from Fire - Requirements, Testing, Marking
Trường học European Committee for Standardization
Chuyên ngành Standardization
Thể loại European Standard
Năm xuất bản 2004
Thành phố Brussels
Định dạng
Số trang 34
Dung lượng 668,68 KB

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Cấu trúc

  • 6.1 General (9)
  • 6.2 Ergonomics (9)
  • 6.3 Design (9)
  • 6.4 Materials (9)
  • 6.5 Mass (10)
  • 6.6 Conditioning (10)
  • 6.7 Connections (10)
  • 6.8 Packaging (10)
  • 6.9 Practical performance (10)
  • 6.10 Leakage (10)
    • 6.10.1 Inward leakage excluding filter penetration (breathing zone) (10)
    • 6.10.2 Leakage into ocular zone (11)
  • 6.11 Filter (11)
    • 6.11.1 Gas capacity (11)
    • 6.11.2 Filter penetration (11)
  • 6.12 Valves (11)
  • 6.13 Breathing resistance (12)
  • 6.14 Flammability (12)
  • 6.15 Carbon dioxide content of inhalation air (12)
  • 6.16 Head harness (12)
  • 6.17 Vision (12)
    • 6.17.1 Visor (12)
    • 6.17.2 Impairment of vision (12)
    • 6.17.3 Field of vision (12)
  • 6.18 Sealing (12)
  • 6.19 Integrity of filtering smoke hood at high carbon monoxide concentrations (13)
  • 6.20 Ingress of humidity (13)
  • 6.21 Temperature of inhaled air (13)
  • 6.22 Communication (13)
  • 7.1 General (13)
  • 7.2 Nominal values and tolerances (13)
  • 7.3 Visual inspection (13)
  • 7.4 Conditioning (14)
    • 7.4.1 General (14)
    • 7.4.2 Mechanical strength (14)
    • 7.4.3 Impact (14)
    • 7.4.4 Resistance of packaging to puncture and tear (14)
    • 7.4.5 Temperature (15)
    • 7.4.6 Pressure changes (15)
  • 7.5 Practical performance test (15)
    • 7.5.1 General (15)
    • 7.5.2 Exercises (16)
  • 7.6 Leakage (16)
    • 7.6.1 Inward leakage excluding filter penetration (breathing zone) (16)
    • 7.6.2 Leakage into ocular zone (16)
  • 7.7 Gas capacity (17)
    • 7.7.1 General (17)
    • 7.7.2 Carbon monoxide test (17)
    • 7.7.3 Other test gases (19)
  • 7.8 Filter penetration (19)
  • 7.9 Breathing resistance (19)
  • 7.10 Flammability (19)
    • 7.10.1 Test specimen (19)
    • 7.10.2 Apparatus (19)
    • 7.10.3 Procedure (19)
  • 7.11 Carbon dioxide content of the inhalation air (20)
  • 7.12 Connections (20)
  • 8.1 General (20)
  • 8.2 Filtering smoke hood or package (20)
  • 8.3 Package (20)

Nội dung

30103990 pdf ¦ ¦ � § ¨ § ¨ ¦ ¦ ¦ EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 403 May 2004 ICS 13 340 30 Supersedes EN 403 1993 English version Respiratory protective devices for self rescue[.]

General

In all tests all test samples shall meet the requirements.

Ergonomics

This standard aims to consider the interaction between the user, the respiratory protective device, and the working environment where the device will be utilized For further details, refer to annex ZA.

Design

The apparatus shall be sufficiently robust to withstand the rough usage it is likely to receive in service with respect to its classification.

The apparatus shall be designed so that there are no protruding parts or sharp edges likely to be caught on projections in narrow passages.

No part of the apparatus likely to be in contact with the wearer shall have sharp edges or burrs.

The apparatus shall be designed to ensure its full function in any orientation.

Testing shall be done in accordance with 7.3 and 7.5.

Materials

Materials which come into direct contact with the wearer's skin shall not be known to be likely to cause irritation or any other adverse effect to health.

All metallic parts shall be corrosion-resistant or protected against corrosion e.g by packaging.

If materials sensitive to humidity are used in the device, they shall be protected against the effects of humidity e.g by suitable packaging.

Testing shall be done in accordance with 7.3, 7.4 and 7.5.

Mass

The mass of the ready-for-use device without packaging or carrying device shall not exceed 1000 g.

Testing shall be done in accordance with 7.1.

Conditioning

Prior to laboratory or practical performance tests all test specimen shall be conditioned.

Testing shall be done in accordance with 7.4.

Connections

Connections between components shall be designed such that they cannot be readily separated by the user. Testing shall be done in accordance with 7.3.

The connection between filter and hood assembly shall withstand axially a tensile force of 50 N.

Testing shall be done in accordance with 7.12.

Packaging

The packaging shall be easy to open without tools.

Testing shall be done in accordance with 7.3.

Practical performance

The entire apparatus will be subjected to practical performance tests to identify any imperfections that may not be revealed by other tests outlined in this standard.

If a test house denies approval due to practical performance tests indicating imperfections affecting the wearer's acceptance, it must provide comprehensive details of the specific tests that identified these issues This transparency allows other test houses to replicate the tests and evaluate the findings.

Testing shall be done in accordance with 7.5.

Leakage

Inward leakage excluding filter penetration (breathing zone)

To ensure effective smoke filtration, smoke hoods must be used according to the provided instructions, achieving a minimum of 46 out of 50 individual results for inward leakage during the specified exercise periods.

5 exercise periods) shall be not greater than

5 % and, in addition, at least 8 out of the 10 individual wearer arithmetic means (10 subjects) for the inward leakage, averaged over all exercise periods shall be not greater than

Testing shall be done in accordance with 7.6.1.

Leakage into ocular zone

The leakage of the test agent shall not exceed 20 %.

Testing shall be done in accordance with 7.6.2.

Filter

Gas capacity

The breakthrough time shall not be less than 15 min when the test agents shown in Table 1 are used.

Testing shall be done in accordance with 7.7.

Test gas Test gas concentration in air a ml/m c (= ppm)

A deviation of ±10% from the required value is acceptable for recorded breakthrough times, which may be adjusted proportionally to align with the specified influent concentration The breakthrough concentration serves as an arbitrary value solely to define the endpoint of filter capacity during laboratory testing.

C C 2 N 2 may sometimes be present in the effluent air The total concentration of (HCN + C 2 N 2 ) shall not exceed 10 ml/m 3 at breakthrough. d Time weighted average in any single 5 min period.

Filter penetration

The filter shall meet the requirements of EN 143 for penetration of particle filter class P2 using sodium chloride as test agent.

Testing shall be done in accordance with 7.8.

Valves

The device may include multiple inhalation and exhalation valves, which must function properly regardless of their orientation Additionally, these valves should be safeguarded against dirt and mechanical damage.

Testing shall be done in accordance with 7.3 and 7.5.

Breathing resistance

The inhalation resistance shall not exceed 8 mbar and the exhalation resistance shall not exceed 3 mbar.Testing shall be done in accordance with 7.9.

Flammability

The materials used shall not present a danger for the wearer and shall not be of highly flammable nature.

The filtering smoke hood and any exposed components must not continue to burn or pose additional risks to the wearer It is not necessary for the filtering smoke hood to remain functional after testing.

Testing shall be done in accordance with 7.3 and 7.10.

Carbon dioxide content of inhalation air

The carbon dioxide content of inhalation air (dead space) shall not exceed an average of 2 % by volume.Testing shall be done in accordance with 7.11.

Head harness

If a harness is fitted it shall meet the requirements for the harness specified in EN 140.

Vision

Visor

The visors shall be reliably assembled to the device.

Testing shall be done in accordance with 7.3 and 7.5.

Impairment of vision

Visors shall not distort vision as determined in practical performance tests There shall be no significant impairment of vision by fogging as determined in practical performance tests.

Testing shall be done in accordance with 7.5.

Field of vision

The field of vision is acceptable if determined so in practical performance tests.

Testing shall be done in accordance 7.5.

Sealing

Each device or filter component must be securely sealed and can only be reopened using specialized equipment The seal should allow for easy access when needed, while preventing accidental opening Additionally, any broken seal should be clearly visible upon inspection.

Testing shall be done in accordance with 7.3 and 7.5.

Integrity of filtering smoke hood at high carbon monoxide concentrations

The device shall maintain its mechanical integrity and shall not present a hazard to the wearer.

Testing shall be done in accordance with 7.7.2.2 but with the variation to use 1,0 % by volume carbon monoxide in air as the test atmosphere, and 7.3.

Ingress of humidity

If materials sensitive to humidity are used these materials shall be protected against humidity.

After conditioning in accordance with 7.4 the device shall meet the requirements of this standard.

Temperature of inhaled air

The temperature of the inhaled air shall not exceed 90 °C dry bulb and 50 °C wet bulb during the test duration of 15 min.

Testing shall be done in accordance with 7.7.2.2 but with the variation to use 0,5 % by volume carbon monoxide in air as the test atmosphere.

Communication

A person wearing the device shall be able to hear verbal communications from the test supervisor.

A person wearing the device shall be able to communicate verbally This does not apply when the device is equipped with a mouthpiece assembly.

Testing shall be done in accordance with 7.5.

General

If no special measuring devices or measuring methods are specified, commonly used methods and devices should be applied.

Before performing tests involving human subjects, account should be taken of any national regulations concerning the medical history, examination or supervision of the test subjects.

Nominal values and tolerances

The standard specifies that nominal values are used unless stated otherwise, with a tolerance of ±5% for unspecified values, excluding temperature limits For testing, the ambient temperature should range from 16 °C to 32 °C, while mechanical tests require a range of 10 °C to 30 °C, with temperature limits accurate to ±1 °C.

Visual inspection

A visual inspection of the filtering devices shall be carried out and the appropriate results reported The visual inspection includes marking and information supplied by the manufacturer.

Conditioning

General

The conditioning procedures outlined in sections 7.4.2 to 7.4.6 must be applied sequentially to all test specimens Additionally, the device should be conditioned in its smallest packaging used for storage or transport.

Mechanical strength

The device shall be tested in its packaging in accordance with 8.3 of EN 141:2000 using 2 000 rotations for 'S' type and 10 000 rotations for 'M' type.

Impact

The device shall be dropped in its packaging six times from a height of 1,5 m onto a smooth concrete surface using different starting orientations.

This conditioning applies only to devices of 'M' type.

Resistance of packaging to puncture and tear

A striker is permitted to drop with a designated energy, aimed downward onto the device as outlined in section 7.4.1 Following the drop, the packaging is removed from beneath the striker's point and examined for any punctures or tears.

Typical test equipment is shown in Figure 1 It consists mainly of a) striker; b) mounting arm for the striker: suitably pivoted; c) smooth polished steel base plate; d) spring balance.

The effective force at rest of the mounting arm and striker must be maintained at 1N ± 2% Adjustments should be made using a spring balance connected to the striker.

The test specimen in its packaging is placed under the striker such that when released the striker hits the packaging.

The impact of the striker shall be from a height of 100 mm.

Leaving the striker in contact with the packaging, briskly pull the packaging away in the direction shown in Figure 1.

Examine the packaging for any puncture or tear.

Temperature

The device shall be in the packaging as described in 7.4.1.

Testing shall be done in accordance with the following clauses of EN 13274-5:2001: a) 6.2.2, 6.3.4 and 6.4.1; b) 6.2.2, 6.3.2 and 6.4.1; c) 6.2.8 and 6.4.2.

Pressure changes

Devices classified as 'M' must be packaged according to the specifications outlined in section 7.4.1, which includes undergoing two pressure change cycles in a test chamber These cycles involve transitioning from ambient pressure to a differential pressure of (-400 ± 10) mbar.

The final pressure must be reached in under 20 seconds, followed by pressure compensation through venting the test chamber after 60 seconds, which should also be completed in less than 20 seconds Additionally, the test chamber will undergo 3,000 pressure change cycles, transitioning from ambient pressure to a differential pressure of (-300 ± 10) mbar.

The final pressure shall be achieved in less than 10 s After 60 s the pressure compensation shall be started and shall be achieved in less than 10 s.

When multiple test specimens are placed in the test chamber to undergo pressure changes, it is essential that they do not come into contact with one another.

Practical performance test

General

For practical performance tests, only devices of the type which passed the laboratory testing shall be worn.

A total of 5 filtering smoke hoods shall be tested.

Prior to the test the filtering smoke hoods shall be examined to ensure that they are in good working condition and can be used without hazard.

For test subjects shall be selected who are familiar with using such or similar devices.

Five test subjects shall be used for the practical performance tests They shall be made familiar with the device using the instructions for use.

The test subjects shall complete the exercises listed in 7.5.2 in a normally lit room at ambient atmosphere and the test temperature and the humidity shall be recorded.

During testing, the device will be evaluated by the wearer, focusing on several key aspects: the comfort of the harness, the security of fastenings and couplings, the accessibility of controls, the clarity of vision through the facepiece visor, the visibility of a sign with letters 100 mm high from a distance of 6 m, communication with the test supervisor, and any additional comments provided by the wearer upon request.

Exercises

The tasks involve: a) walking for 5 minutes in an area with a headroom of (1.3 ± 0.2) m; b) crawling for 5 minutes in a space with a headroom of (0.7 ± 0.05) m; and c) filling a small basket, approximately 8 liters in volume, with rubber chippings or similar material from a hopper that is 1.5 m high The hopper features a bottom opening for shoveling out the contents and a top opening for returning the filled basket.

The individual may choose to stoop or kneel while filling a basket with rubber chippings Afterward, they will lift the basket and pour its contents back into the hopper This process is to be repeated 15 times within a duration of 5 minutes.

Leakage

Inward leakage excluding filter penetration (breathing zone)

Test subjects, number of test specimen and preparation of test specimen in accordance with EN 405.

Testing in accordance with EN 13274-1, test method 1 using sulfur hexafluoride as test agent.

Leakage into ocular zone

7.6.2.1 Number of test specimens and test subjects

For the test 10 test specimen and 10 test subjects shall be used.

The visor in the hood shall be prepared by perforating such that a sampling probe and a thin air supply hose can be inserted in a leak tight manner by appropriate plugs.

The sampling probe must be placed at eye level inside the hood, while the air supply hose port should be positioned slightly below eye level on the opposite side to avoid causing distress to the test subject Additionally, a third hole should be created between the sampling probe and air supply ports for connecting a sensitive differential pressure meter with a sensitivity of less than 0.01 mbar.

The test subject wearing the hood prepared as described in 7.6.2.2 shall stand on a treadmill.

A continuous sample flow rate of 0.5 l/min must be supplied through the sampling line to the flame photometer, and if needed, it should be diluted with clean air to meet the photometer's minimum flow rate requirements.

Clean air will be supplied to the hood at a flow rate of 0.5 l/min Adjustments to the airflow will be made to ensure that the pressure inside the hood matches the ambient pressure while the test subject remains standing and still.

NOTE Sometimes it may be necessary for the test subject to hold his breath for this procedure.

Testing shall be done in accordance with EN 12941 using sodium chloride as test agent.

At the conclusion of the test, the concentration of the challenge in the test chamber will be assessed using the same flow rates and dilution conditions that were utilized for measuring the in-hood concentrations.

The leakage into the ocular area LH will be determined using measurements taken during the final 100 seconds of each exercise period, ensuring that results from one exercise do not influence another.

LH(%) ion concentrat challenge level eye at ion concentrat x 100

Gas capacity

General

The gas capacity will be evaluated using three filters for each test gas under various conditions When testing a single filter from a multi-filter device, the specified airflow for the test must be divided by the total number of filters to ensure accurate results.

Carbon monoxide test

Figures 3, 4, 5, and 6 illustrate schematic diagrams of suitable test arrangements, which include a breathing machine with solenoid valves, a humidifier, air and carbon monoxide flow meters, a test chamber with sampling ports and exhaust, carbon monoxide analyzers, and measurement tools for pressure, temperature, and moisture content, along with a 'Sheffield' dummy or appropriate adapter and a carbon monoxide supply.

The hood will be tested when mounted on the Sheffield dummy head, and if the filter is tested separately, it must be attached to an appropriate adapter The testing process will also include the valves of the hood, if they are applicable.

NOTE 1 It may be necessary to use a sealant to ensure an effective seal between the hood and the dummy head (Sheffield) or adapter respectively.

The test chamber will be supplied with a minimum airflow of 100 l/min, containing carbon monoxide and water vapor, regulated by control valves and flow meters The breathing machine will be set to operate at 20 cycles per minute with a stroke volume of 1.5 liters.

Concentration of carbon monoxide 0,25 % by volume

Humidity (moisture content of test atmosphere) 20,7 g/m3

The temperature and humidity of the test atmosphere and exhalation air shall be controlled by using suitable conditioners.

During the test, the concentrations of carbon monoxide and water vapor, along with the differential pressure, will be continuously monitored and recorded 2.5 cm in front of the air inlet of the test specimen.

NOTE 2 The effect of differential pressure and of the dilution of the challenge atmosphere by exhaled air shall be taken into account and the concentration of carbon monoxide and moisture shall be adjusted accordingly.

The breathing resistance and the carbon monoxide concentration (ml/m 3 ) shall be measured and recorded continuously.

When evaluating air quality, the dry bulb temperature of inhaled air must be measured using a fast response thermocouple, such as a NiCr-Ni with a 0.2 mm diameter, in an atmosphere containing 0.5% by volume carbon monoxide Additionally, the moisture content of the inhaled air should be continuously monitored, with a suitable method outlined in annex A.

The test shall be repeated but with the variation to use 0,5 %, 0,75 %, and 1,0 % by volume carbon monoxide in air until all four values have been used.

NOTE Four concentrations are used to establish the catalytic characteristics of the materials and the configuration of the device.

The carbon monoxide concentration of the inhaled air shall not exceed 200 ml/m3 time weighted average in any single 5 min period.

Other test gases

The conditions shown in Table 1 shall be used for testing with the gases specified in 6.11.1.

The filter under test shall be connected to a test rig generating a continuous air flow of 30 l/min (± 3 %) with the required concentration of test gas.

The test atmosphere shall be at a temperature of (20 ± 1) °C and shall have a relative humidity of (70 ± 5) %. When hydrogen chloride is used as a test gas the relative humidity shall be (30 ± 10) %.

The breakthrough concentration shall be monitored with a maximum error of 20 % The breakthrough time shall be stated in minutes.

Filter penetration

Testing in accordance with 8.7.2 of EN 143:2000 using 3 filters and sodium chloride aerosol.

If separate testing of the filter is not possible, applying a sealant may be essential to achieve a proper seal between the hood and the Sheffield dummy head or adapter.

When testing a single filter in a multi-filter device, the specified air flow for the test must be divided by the total number of filters that the air flow is distributed through.

Breathing resistance

Two filtering smoke hoods shall be tested.

The device must be installed on a Sheffield dummy head, and the breathing resistance will be assessed at the mouth using a breathing machine set to 1.5 l/stroke and 20 cycles per minute, following the procedure outlined in section 7.7.2.2 Additionally, the flow rate for measuring resistance will be adjusted to standard conditions of 23 °C and 1 bar absolute.

Flammability

Test specimen

Two filtering smoke hoods shall be tested.

Apparatus

The test rig described in EN13274-4 method 1 is used.

Procedure

The filtering smoke hood must be securely attached to a metallic dummy head In cases where the smoke hood lacks a head harness, it should be properly clamped in a device to ensure that the material remains horizontal.

The distance between the outer surface of the filtering smoke hood and the burner tips shall be adjusted to

The pressure reducer should be set to around 0.15 bar, ensuring that the propane gas control device on the burners is fully opened while the air control device is completely closed The flame temperature, measured 250 mm above the burner tip, must be maintained at (800 ± 50) °C.

The filtering smoke hood (on the dummy head) or the filtering smoke hood material (in the clamp) shall be rotated once through the flame at a velocity of (6 ± 0,5) cm/s.

The test must be conducted again with components like valves and filters positioned at the correct height of 250 mm above the flame, as they are integrated into other parts of the filtering smoke hood.

After exposure to the flame, it will be documented whether the filtering smoke hood or other components ignited or posed any further risks to the wearer.

Carbon dioxide content of the inhalation air

Two filtering smoke hood shall be tested.

Testing shall be done in accordance with EN 136.

Connections

Two filtering smoke hood shall be tested.

The test duration will be 10 seconds, during which the filtering smoke hood must be positioned on a dummy head It is essential to adjust the setup so that the load is applied axially to the connection, as illustrated in Figure 7.

General

All the markings shall be readable and durable.

Sub-assemblies and piece parts with considerable bearing on safety shall be marked so that they can be identified.

Filtering smoke hood or package

All filtering smoke hoods must be labeled with the date and number of the relevant European Standard, along with any applicable classification Additionally, the identity of the manufacturer, supplier, or importer should be clearly indicated through their name, trademark, or other identification methods Lastly, the manufacturer's model designation must also be included on the packaging.

Package

The package must include essential information such as the class designation ('M' or 'S'), the date of manufacture along with the end of shelf life or next inspection date, and the manufacturer's recommended storage conditions, including temperature and humidity Additionally, it should feature the phrase "See information supplied by the manufacturer" in the official language(s) of the destination country, or an equivalent pictogram If the device's performance could be compromised by mass increase due to humidity absorption, the packaging must indicate the mass and provide protection against humidity Lastly, if the device includes a mouthpiece and nose clip, it should state: "Do not speak during use."

9 Information supplied by the manufacturer

The manufacturer must provide essential information with every device, including details in the official language of the destination country This information should cover application limitations, single-use duration, suitability for children, and the prevention of speech when using a mouthpiece It must also include instructions on controls, donning, fitting, maintenance, storage, and shelf life Special emphasis should be placed on self-rescue and the lack of protection against oxygen deficiency Warnings about potential issues, such as avoiding damage and following donning procedures, are necessary The information must be clear and comprehensible, with helpful illustrations if needed, and should be accessible without breaking any seals Additionally, an explanation of the symbols used should be provided.

7.3 Visual inspection 7.4 7.3 Visual inspection All

6.9 Practical performance 7.4 7.5 Practical performance test 5

6.10.1 Inward leakage excluding filter penetration (breathing zone)

7.4 7.6.1 Inward leakage excluding filter penetration (breathing zone)

6.10.2 Leakage into ocular zone 7.4 7.6.2 Leakage into ocular zone 10

6.15 Carbon dioxide content of inhalation air 7.4 7.11 Carbon dioxide content of the inhalation air 2

6.17.2 Impairment of vision 7.4 7.5 Practical performance test 5

6.17.3 Field of vision 7.4 7.5 Practical performance test 5

6.19 Integrity of filtering smoke hood at high carbon monoxide concentrations

6.20 Ingress of humidity 7.4 7.4 Conditioning All

6.21 Temperature of inhaled air 7.4 7.7.2.2 Procedure 3

9 Information supplied by the manufacturer 7.4 7.3 Visual inspection All a Most samples are used for more than one test.

2 Mounting arm for the striker

Figure 1 — Scheme of typical equipment for testing puncture and tear resistance

Figure 2 — Hopper and basket, rubber chippings

6 Sampling port CO-content (inhaled air)

8 Flow meter for test atmosphere

9 Flow meter for carbon monoxide

11 Test chamber (dimensions appr 30 cm x 30 cm x 26 cm)

12 Sampling port, CO-content of test atmosphere at filtering device inlet

13 Test specimen under test (max pressure difference at filtering device inlet with regard to ambient in the test chamber + 0,5 mbar)

15 Temperature measurement equipment with plotter

16 Carbon monoxide analyser & recorder (inhaled air ml/m 3 and ml)

17 Carbon monoxide analyser (test atmosphere)

Figure 3 — Scheme of test equipment for testing carbon monoxide performance using filter adapter

3 CO-analyser 12 Test specimen under test

7 Dew point meter 16 Flow meter

8 Exhalation temperature and pressure measuring equipment 17 Air in

9 Inhalation temperature and pressure measuring equipment

Figure 4 — Scheme of test equipment for testing carbon monoxide performance using dummy head

1 To pressure gauge (for measurement of breathing resistance)

4 Pressure port with ‘Button’ Probe (for measurement of breathing resistance)

Figure 5 — Dummy head (Sheffield head) for testing gas capacity, carbon dioxide content of inhalation air and breathing resistance

1 Location of sampling port for breathing resistance

Figure 6 — Typical arrangement of an alternative connector for dummy head

Figure 7 — Scheme of test arrangement for tensile force

Method for the determination of wet bulb temperature of the inhaled air

A schematic arrangement of a suitable apparatus is shown in Figure A1.

A continuous air sample will be extracted from the inhalation breathing path at a constant flow rate of 0.1 l/min and directed through the sensor head block To ensure accurate measurements, all sample lines and the sensor head block must be heated to at least 10 °C above the expected dew point temperature, which will be recorded during the test Additionally, the dry bulb temperature will be measured as specified in section 7.7.2.2.

The wet bulb temperature then shall be determined using the following calculation.

At the dew point temperature, the gas is fully saturated Hence, the relative humidity (RH) is given by:

RH (%) e temperatur bulb dry at pressure vapour saturation e temperatur point dew at pressure vapour saturation x 100 (A.1)

Saturation vapour pressure at temperature t shall be obtained from the following equation: log 10 (e") t H

+ + l (A.2) where e" is the saturation vapour pressure (mbar) t is the dry bulb temperature (°C)

After measuring the dry bulb temperature and determining the relative humidity using equations (A.1) and (A.2), the wet bulb depression can be calculated, allowing for the determination of the wet bulb temperature from standard psychrometric tables.

7 Stainless steel sensor head block

Figure A.1 — Schematic arrangement for the determination of wet bulb temperature of the inhaled air

Clauses of this European Standard addressing essential requirements or other provisions of EU Directives

This European Standard 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 89/686/EEC.

WARNING: Other requirements and other EU Directives may be applicable to the products falling within the scope of this standard.

The clauses of this European Standard are likely to support requirements of Directive 89/686/EEC, Annex II:

Table ZA.1 — Relationship between this standard and the EU Directive 89/686/EEC

Basic Requirements (EU Directive 89/686/EEC, Annex II) Clauses of this standard

1.1.2.1 Highest level of protection possible 6.9

1.2.1 Absence of risks and other inherent nuisance factors 6.3, 6.4, 6.18, 6.21

1.2.1.2 Satisfactory surface condition of all PPE parts in contact with the user 6.3, 6.9

1.3.1 Adaptation of PPE to user morphology 6.9, 6.16

1.4 Information supplied by the manufacturer 9

2.3 PPE for the face, eyes and respiratory tracts 6.9, 6.17

2.8 PPE for use in very dangerous situations 9

2.12 PPE bearing identification marks related to health and safety 8

3.6.1 Protection against heat and/or fire

PPE constituent materials and other components

Compliance with this standard provides one means of conforming with the specific essential requirements of the Directive concerned and associated EFTA regulations.

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