Dwyer 400 - Manual

1. Remove gage from case. Set up in vertical position using (a) gage stand
and leveling screw or (b) Magneclips on a vertical steel surface.
2. Turn connectors counterclockwise 1/2 to 3/4 turns, thus venting gage to
atmosphere.
3. Center bubble between cross hairs on spirit level with leveling screw or by
shifting gage position.
4. Turn fluid level adjustment knob to set the meniscus of the fluid column at
zero, as in sketch.
Align fluid meniscus and the reflected image to eliminate parallax error.
5. Add or remove fluid as necessary.
6. Use left hand gage connection for plus (above atmospheric) pressures.
Connect to right side for minus (below atmospheric) pressures. Connect to
both sides for differential pressures, as with a Pitot tube.
CAUTION:
Use only Dwyer
® gage fluid. Clean with mild soap and water only. Other fluids,
solvents or cleaning agents may damage the gage.
AIR VELOCITY
The total pressure of an air stream flowing in a duct is the sum of the static or
bursting pressure exerted upon the sidewalls of the duct and the impact or
velocity pressure of the moving air. Through the use of a Pitot tube connected
differentially to a manometer, the velocity pressure alone is indicated and the
corresponding air velocity determined.
Series 400 Air Velocity Meter
Operating Instructions and Parts List
Bulletin H-7
DWYER INSTRUMENTS INC.
MICHIGAN CITY, IN 46360 U.S.A.
H-7:Bulletin D-2 10/14/10 11:39 AM Page 1