Heraeus HS 9 Service Manual page 192

Testing Safety Cabinet Class II according to EN 12 469
HS / HSP
Visual check
• Labels, warnings
• Scratches
• Exhaust connection
• Options
Electrical safety test ( VDE )
Ground conductor ( Schutzleiter )
•
Insulation resistance ( Isolationswiderstand )
•
Leakage current ( Ableitstrom )
•
Air direction test
• Adjust front window to working position ( 200 mm )
• Slide along the window opening with smoke tube
• Air flow direction from outside to inside
( no refluxing, no visible turbulence )
Inflow air velocity test
Inflow air speed (method 1)
Adjust front window to an opening of 5 cm
•
Measuring air velocity in the middle in steps of
•
10 cm (start with 5 cm)
Inflow air can be calculated: v
•
Exhaust air speed (method 2)
Place the measuring frame over the exhaust
•
filter opening and seal with adhesive tape
Measure air velocity according to 5-position
•
method
Inflow air can be calculated: v
•
Laminar air flow test
Cabinet in operation ( at least 20 min.)
•
Adjust anemometer 5 cm above front window
•
opening
Measuring grid: of the edge 15 cm,
•
between measure point 30 cm
Measure air velocity (wait 1 min.)
•
Mean value of air velocity: 0,25 - 0,5 m/s + 20 %
•
If air velocity is too low, test the following:
• Voltage of the fans
• Exhaust connection
• Ducting system
Filter leakage test (DEHS- test)
Main filter and exhaust filter
• Turn cabinet on
• Calibrate particle counter
• Place aerosol generator in the cabinet
• Connect rarefaction between particle counter and
test connection (under working plate)
Testing HS / HSP
• Only HSP: Remove rubber seal from bypass opening
• Switch on aerosol generator
• Measure particles at the dirty side of main or exhaust
• Required value: 30 mil. particles of size 0.3 µm
• Disconnect the particle counter from the rarefaction
• Scan the seat of the sealing an the clean side of the
• Limit value of particles > 300 St./ 0.3 µm
• If max. number of particles is exceeded change filter.
Monitoring equipment, acoustic and visual alarm
• Cabinet in operation
• Measure fan voltage
• Perform test for laminar air ( mean value 0,40 m/s )
__
= v / 4
2 2
= v x A /A
2 1 1 2
• Return fan voltage to the measured value
• Turn cabinet off and on, check operation
Fill out test protocol and paste up inspection sticker
Additional: KI-Discus test (personnel protection test)
• Cabinet in operation (at least 20 min)
• Reduce air movements in laboratory ( close doors,
• Install KI-Discus equipment according to its operating
• Do measurement 5 times according to instruction
• Count potassium iodide particles on filter paper
• Calculate protection factor
• Limit < 60 particles
• For deviations: repeat measurement 2 times
• Check air flow in laboratory, check filter sealing
Ingo Nierobisch
filter, 5 measurements (each for 1 min)
and connect to the measuring-head
main filter. Speed of scanning < 5 cm/sec, distance
max. 1 cm.
Adjust lower limit pressure switch
Find out point with lowest air velocity
•
Set anemometer in this point, measure air
•
velocity
Set fan voltage so that at this measuring point air
•
velocity is mean value -20 % ( 0,32 m/s )
Change adjustment of lower pressure switch it
•
just turns on. Visual and acoustic alarm goes on
Adjust upper limit pressure switch
Find out point with highest air velocity
•
Set anemometer in this point, measure air
•
velocity
Set fan voltage so that at this measuring point air
•
velocity is mean value +20 % ( 0,48 m/s )
Change adjustment of upper pressure switch it
•
just turns on. Visual and acoustic alarm goes on
windows, air condition, ... )
instruction
14.06.02