Heraeus HS 9 Service Manual page 180

Manufacturing site / Year
Testing Safety Cabinet Class II Type A2
Air inflow speed: Method 2
Direct measuring inflow air volume in the front window opening with Hot-wire anemometer and compensation factor (on the data plate)
Front panel opening height 3 in (76 mm), measuring points side distance 4 in (10 cm), height 1.5 in (38 mm)
Ft/
1 2
min
Ft/
7 8
min
Ft/
13 14
min
Mean air speed in relation to height of working opening
Set value : 105 ft/min + 5 ft/min (0,53 m/s + 0,025 m/s)
Remarks:
Downflow velocity test
Mean downflow velocity, Set value 70 ft/min ( See on data plate ) > + 5 ft/min
Measuring level 50 cm above window opening, set-points for the individual device types are listed on the data plate !
Ft/
1 2
min
Ft/
7 8
min
Ft/
13 14
min
Ft/
19 20ß
min
Ft/
25 26
min
Ft/
31 32
min
No individual measuring must deviate more than + 20% or + 16 ft/min (+ 0.081 m/s) from mean value!
Remarks:
Site installation assessment tests
Airflow alarms : audible and visual alarms indicates incorrect air flow conditions
( 20% loss of exhaust volume in 15 s)
Sash alarm : system warns of unsafe view screen opening [indicates deviation of + 1.0 in (2,5 cm) ]
Exhaust system performance - canopy connection: No smoke escape into the room.
Remarks:
Order no.:
Hot-Wire Anemometer
Ft/ Ft/
3
min min
Ft/ Ft/
9
min min
Ft/ Ft/
15
min min
Target value = Mean air speed / 3.33 x compensation factor
Requirement fulfilled
Ft/ Ft/
3
min min
Ft/ Ft/
9
min min
Ft/ Ft/
15
min min
Ft/ Ft/
21
min min
Ft/ Ft/
27
min min
Ft/ Ft/
33
min min
Sheet:
2/3
according to NSF/ANSI 49 - 2002
Ft/
4 5
min
Ft/
10 11
min
Ft/
16 17
min
(+ 0.025 m/s)
Ft/
4 5
min
Ft/
10 11
min
Ft/
16 17
min
Ft/
22 23
min
Ft/
28 29
min
Mean value downflow velocity
Ft/
6
min
Ft/
12
min
Ft/
18
min
Yes No
Testing grid measuring points
A = 4 in (10 cm) distance
over window opening
B = 6 in (15 cm) distance
between side walls
C = 6 in (15 cm) distance between
test area and front window
D = 6 in (15 cm) distance between
test area and rear wall
Ft/
6
min
Ft/
12
min
Ft/
18
min
Ft/
24
min
Ft/
30
min
Requirement
Yes
fulfilled
Yes No
Yes No
Yes No
Ft/
min
Ft/
min
Ft/
min
Ft/
min
Ft/
min
Ft/
min
Ft/
min
Ft/
min
Ft/
min
Ft/
min
No