AS ISO 16900.4 pdf download – Respiratory protective devices—Methods of test and test equipmentPart 4: Determination of gas filter capacity and migration, desorption and carbon monoxide dynamic testing.
8.1 General
Prior to testing, the test specimen shal be stored in its smallest available commercial packaging for a minimum of 4 h at (21 3) °C, unless otherwise specified in the performance standard. The test specimen shall be mounted in the test chamber and exposed to the appropriate gas challenge at the specified flow.
The specimen and its primary attachment shall be exposed to the challenge gas such that leakage at the primary attachment point can be detected. The connector shall be sealed within the chamber so that no leakage can occur where the connector is intended to be attached to the respiratory interface
The above conditions can readily be achieved lithe specimen is fitted with a standardized connector Ii the specimen is equipped with a non-standardized connector, the required fitting can be obtained from the manufacturer or by disassembly of a suitable device, Where the gas filter(s) is (are) an integral part of the RPD, the whole device shall be effectively sealed to a mount within the test chamber
Any experimental method may be employed to obtain the specified influent concentration and measure the effluent concentration, provided it conforms to the following limits:
a) influent concentration: ±10 % of specified challenge value;
b) effluent concentration: ±20% of specified breakthrough value.
8.2 Test flow conditions
8.2.1 General
All tests shall be conducted so that the test gas flows horizontally and wi line with the rrwnimum bed depth of the filter. Care shall be taken that the test gas Is not directed preferentially on to one part of the filter or filter system.
The concentration of the test gas shall be stabilized before the test is started
8.2.2 MultIple filters
When one filter of a multiple filter device is tested separately, the air flow specified for a test shall be divided by the number of filters through which the aw flow is proportioned. If. however, it is possible to use only one filter of a multiple filter device, then the full air flow shall be used for testing
lithe filters’ resistances are in accordance with Equation (1). then the filter may be tested as a single filter with a proporlioned flow. If the filters’ breathing resistances are not in accordance with Equation (1), the fillers shall be tested in a complete unit at the full flow rate
After exposure, the filters shall be Stored for (66 ± 6) h, according to the mformation supplied by the manufacturer for between-use storage. After storage, test gas shall be passed throu the filler at the flow rate, humidity and temperature given in the performance standard.
The duration of the migration test and the conditions for terminating the test shall be specified in the performance standard. The concentration of the lest gas and specified reaction products. if applicable, in the effluent air shall be continuously recorded during this test.
8.6 Desorption test
The filters shall be exposed to the test gas as specified in the performance standard
Immediately after exposure, clean air shall be passed through the filter at the flow rate, hu,mdity and temperature used in the gas filter capacity test The duration of the desorption test and the conditions for terminating the test shall be specified in the performance standard. The concentration of the preadsorbed agent and specified reaction products, if applicable, in the effluent aw shall be continuously recorded during this test.
9 Test report
9.1 General
The lest report shall include information regarding those perametera specified in Clause 4 together with the information given in 9.2 to 96.
9.2 Gas capacity test
Report the corrected breakthrough tm’e or the test time, or the fact that breakthrough did not occur.
9.3 Gas filter validation test at specified flow rates
Report whether or not breakthrough occurred before the minimum specified time and report the actual breakthrough time in cases where the application of the alternative method (Annex B) is to be used,
9.4 MigratIon test
Report the maximum concentration of the test gas and the reaction product(s), if applicable, in the effluent air and the corresponding time
9.5 Desorptlon test
Report the maximum concentration of the test gas and the reaction product(s), if applicable, in the effluent air and the corresponding time
9.6 CO dynamic test
Report the effluent CO concentration over time and the integral dose.
AS ISO 16900.4 pdf download – Respiratory protective devices—Methods of test and test equipmentPart 4: Determination of gas filter capacity and migration, desorption and carbon monoxide dynamic testing
