ISO 16900-1:2014 pdf free

ISO 16900-1:2014 pdf free.Respiratory protective devices一Methods of test and test equipment
The probe shall be fitted securely to the respiratory interface, terminating as near as possible to the wearer’s face (<10 mm) and approximately midway between the nose and mouth.
Where necessary, for flexible, soft, or lightweight respiratory interfaces, employ a means to support the weight of the probe assembly and associated tubing, e.g. a head harness, to prevent distortion of the respiratory interface. This distortion can alter the face seal causing additional leakage.
A second sampling probe (identical to the first) shall be used to measure the ambient concentration of test agent in the test enclosure. This shall be placed close to the RPD, but away from the effect of any exhalation from the RPD under test. The sampling probes shall be connected to the analysing equipment by means of flexible thin-walled tubing of about 3 mm bore, the length of which shall be kept as short as possible. The two sampling tubes shall be of the same type and length.
Where the performance standard requires that a sample be withdrawn from the ocular region of the respiratory interface, the sampling probe shall be positioned on one side of the test subject at eye level and make up air might be required.
Care shall be taken to ensure that the sample tubes and probe do not disturb the normal fit or shape of the respiratory interface.
Sample flow rates shall be between 0,3 l/min and 2 l/min, depending on the detection system. The sample flow rate shall be kept as low as possible so as not to change the designed performance of the RPD being tested.
It might be necessary to supply a compensating airflow when sampling from an area of the RPD through which, under normal conditions of use, there is no airflow, e.g. when sampling from the ocular region.Position the compensating airflow such that it does not cause sampling bias nor distress the wearer.
When sodium chloride is used to test negative pressure devices, drying air at a flow of about 1 l/min is added to minimize condensation and hence loss of sodium chloride particles in the sampling tube.The sample flow rate from the respiratory interface is equal to the total flow through the sample pump minus the flow rate of dry air. A correction shall be made for the diluting effect of this dry air when leakage calculations are performed (see 1.3.2.2 and 11.3.3.2). Dry air is not required if gas or corn oil aerosol is the test agent.ISO 16900-1 pdf download.