ISO 21904-2-2020 pdf download.Health and safety in welding and allied processes一Equipment for capture and separation of welding fume – Part 2: Requirements for testing and marking of separation efficiency.
6 Test method
6.1 Selection of test arrangement
Use the test cabin illustrated in Figure 1 or the test arrangement snown in Hgurez. Any we’ding rume separation equipment (including individual modules of a modular system) can be tested using the test cabin depicted in Figure 1. provided it can be fitted into the test cabin. For an example of a test cabin, see Annex A.
Only welding fume separation equipment with a ducted outlet can be tested using the arrangement shown in Figure 2.
6.2 Test conditions
Carry out the test under conditions that are similar to the normal working conditions for the equipment under test.
For modular welding fume separation equipment, if the designed air volume flow rate is greater than 2 000 m3/h, carry out the test of separation efficiency using a specially made scaled down typical module. If different fans can be used in combination with the welding fume separation equipment, carry out the test of separation efficiency using the minimum and maximum air volume flow rates recommended by the manufacturer.
6.3 Procedure
6.3.1 Source emission rate measurement
Determine the emission rate of the welding fume source using the exact conditions used during testing and the general approach specified in ISO 15011-1. Weld while sampling total welding fume emission on a preweighed filter. Stop welding and sampling and reweigh the filter. Calculate the emission rate by dividing the mass of welding fume collected on the filter by the sampling time.
6.3.2 Equipment without filter cleaning system
Select the test arrangement and set up the test conditions.
— Determine the source emission rate as described in 3.1.
— Switch on the welding fume separation equipment, the air volume flow rate measurement systems and the air mover in the downstream measurement duct. Adjust the air volume flow rate in the upstream duct using the dampers to the air volume flow rate stated by the manufacturer.
— Monitor the air volume flow rate throughout the test.
— Generate and separate welding fume for an arcing period of 30 mm without measurement in order to precondition the separation equipment. Use precoated filters to test equipment with mechanical separation systems, if the manufacturer intends their use.
— Commence sampling and collect samples of welding fume for an arcing period of 30 mm.
— Continue welding for a further arcing period of 60 mm without measurement (see Figure 3) and record the air volume flow rate at the end.
— When the test is completed, repeat the determination of the source emission rate and average the results of the first and second emission rate determinations. The average value should be 10 mg/s ± 2 mg/s.ISO 21904-2 pdf download.