Dwyer AFH2 - Manual (Page 2)

Bulletin AV-4-AFH2
The Model AFH2 Air Flow Hood is designed to measure differential air
pressure in and around commercial and industrial air handling systems.
The AFH2 Air Flow Hood maintains a running average of measurements
in the desired system. Using this product, you will have the ability to
manually record measurements with the manometer on a given time
interval. This unit also has an auto-zero feature and will auto-zero at
user-defined intervals (this statement does not apply to l/sec, m
3 /hr or
cfm mode, these modes are factory set to auto-zero every 10 seconds
and this cannot be changed by the user). In addition to these features,
the unit will alert you when its battery is running low in order to avoid
recording inaccurate measurements. This lightweight flow hood is
durable and easily stores in included travel case. New low flow adapter
kit allows easy conversion of any AFH2 into a low flow hood. All kits fit
easily into the AFH2’s travel case.
SECTION 1: INTRODUCTION
1.1
Do not use the digital manometer/capture hood unit for liquid or gas
mixtures other than air. No responsibility will be taken by Dwyer
Instruments, Inc. for any resulting damage to the unit or to operators if it
is used with corrosive or other dangerous or explosive gas mixtures.
When using the digital manometer/capture hood to check air flow at
ceiling diffusers, make certain that you can raise and hold the unit safely
during use. This instrument is not classified as flameproof or intrinsically
safe; therefore they must not be used where an explosion hazard may
exist. The unit is not authorized for use on life support applications.
Note: Observe standard safety procedures when working on ladders
and scaffolding. Also ensure the unit does not become caught in moving
machinery or on sharp objects.
Specifications - Installation and Operating Instructions
Model AFH2 Air Flow Hood
ITEMS INClUDED WITH THE AFH2 HOOD
1. Base unit with 2’ x 2’
(600 mm x 600 mm) hood.
2. Micromanometer
3. Carrying case
4. 1 pair of suction cup
handles
5. 1 accessory pack (4
tubing adapters 2 mm x 6
mm, 1 neck sling, 2 bore
flexible tubing 3 m x 2 mm)
1.2
• If stored under conditions outside normal operating range, allow the
unit to stabilize at room conditions before use.
• Owing to its size and shape, take care when carrying the assembled
unit from place to place.
• Avoid people and near-by equipment.
• Avoid sharp objects that may tear the capture hood.
• Turn the instrument off before storage or transportation and remove the
batteries if storing for long periods or transporting by air.
• Make sure that the bellmouth/capture hood cable is not pinched by the
mounting system. When not in use, the connector can be tucked behind
the mount.
• Avoid subjecting the bellmouth sensing grid to excessive loading during
use or assembly. Any air flow other than through the calibrated sensing
holes, such as any hair-line cracks, will seriously affect the sensitivity.
• A damaged bellmouth sensing grid must be replaced, it cannot be
repaired.
• Take care when fitting different sized canvas hoods of the protruding
pins at the bellmouth.
• Do not disassemble the bellmouth sensing grid from the bellmouth
molding. The retaining structure is specifically designed to
accommodate loading due to normal operation.
• Under low humidity conditions, static electric charges may be
encountered. These can be avoided by applying a suitable anti-static
solution.
24 SQ. [609.60]
38
[965.20]
MOUNTING
PLATE
HOOD FRAME ASSEMBLY
8
[203.20]
18-1/2 [469.90]
CAUTION
WARNING