3. To surface-mount the gage, drill two
5/32″ [3.97 mm] holes on a horizontal
line, 2-1/3″ [59.26 mm] apart for
mounting screws. Next, drill two
7/16” [11.11 mm] holes 1-1/32″
[26.19 mm] apart on a vertical line for
pressure connections. Install mounting studs in back of the gage, insert
through holes in the panel, and secure
with hex nuts provided. Be careful not
to block the slotted hole near the
right-hand mounting hole. This provides a path for pressure relief in the
event of over-pressurization.
4. To panel-mount gage, cut a 2-5/8″
diameter hole. Install the mounting
studs in the back of gage, position
gage in the panel, and place bracket
over the studs. Thread hex nuts over
studs and tighten.
5. After installation, the gage may
need to be zeroed before placing in
operation. If re-zeroing is required,
firmly hold the case of gage with one
hand and unscrew the front cover with
the palm of the other hand in a counterclockwise direction. If difficult to
loosen, place a small sheet of rubber
between the cover and the palm of the
hand. Zero-adjust screw is located
behind the scale at the pair marked
“zero.” Use the hex allen wrench
supplied and adjust until pointer is
on zero. This must be done with
both pressure connections vented
to atmosphere and the gage oriented in the final mounting position.
Replace cover.
6. To measure positive pressure,
connect tubing to port marked “HI”
and vent “LO” port to atmosphere.
For negative pressure (vacuum),
connect to port marked “LO” and
vent “HI” port to atmosphere. For
differential pressure, connect higher
pressure to port marked “HI” and
lower to “LO” port. If gage is supplied with 1/8″ NPT connections, be
careful not to over-tighten fittings to
avoid damage to the gage.
CALIBRATION CHECK
Select a second gage or manometer
of known accuracy and in an appropriate range. Use short lengths of
rubber or vinyl tubing to connect
the high-pressure side of the
Minihelic®II gage and the test gage
to two legs of a tee. Very slowly,
apply pressure through the third leg.
Allow enough time for pressure
to equalize throughout the system
and for fluid to drain. if a manometer
is being used. Compare readings.
If the gage being tested exceeds
rated accuracy, it should be
returned to the factory for recalibration.
MAINTENANCE
No lubrication or periodic servicing
is required. Keep case exterior and
cover clean. Occasionally, disconnect pressure lines to vent both
sides of the gage to atmosphere
and re-zero per paragraph 5.
PANEL MOUNTED INSTALLATION
Bulletin A-36
©Copyright 2009 Dwyer Instruments, Inc Printed in U.S.A. 7/09 FR# 14-440434-00 Rev. 2
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, IN 46361, U.S.A. Fax: 219/872-9057
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