©Copyright 2012 Dwyer Instruments, Inc.
Printed in U.S.A. 4/12
FR# 72-444019-00 Rev. 1
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000
www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: 219/872-9057
e-mail: info@dwyer-inst.com
Figure 1:
View illustration of probe placement example.
Please note that all probes should be installed vertically and
running parallel to each other if installed in a rectangular duct.
RECTANGULAR DUCT PROBE INSTALLATION
1. See drawing for proper opening to cut for insertion. Cut a hole at
locations calculated above in side of duct. Drill a 5/16˝ hole on
opposite side of duct. Remove o-ring, hex and acorn nuts.
2. Place silicon bead around holes.
3. Slide MAFS into holes and screw the included four self drilling
screws into duct to attach MAFS. On far end, re-attach o-ring, hex
and acorn nuts.
4. Connect 3/16˝ I.D. tubing to barb fittings on MAFS.
5. Check all fittings and tubing connections for leaks using a leak
detector.
6. Tee all high and low ports into one high and one low line and connect
to transmitter or gage.
7. The devices should be checked occassionally for build-up of dirt of
debris common in an HVAC system.
CIRCULAR DUCT MODELS
Determining Probe Number and Location for Round Ducts
1. Note that in round ducts only two probes are needed. The quantity
of probes needed does not depend on size of the duct.
2. Locate probes 90 degrees apart. See Figure 2 for an example.
Figure 2:
Cross-sectional view of probe placement in a round duct.
DAFM
D
A
F
M
90°
ROUND DUCT PROBE INSTALLATION
1. See drawing for proper opening to cut for insertion. Cut a hole at
locations calculated above in side of duct. Drill a 5/16˝ hole on
opposite side of duct. Remove o-ring, hex and acorn nuts.
2. Place silicon bead around holes.
3. Slide MAFS into holes and screw four self drilling screws into duct to
attach MAFS. On far end, re-attach o-ring, hex and acorn nuts.
4. Connect 3/16˝ I.D. tubing to barb fittings on MAFS.
5. Check all fittings and tubing connections for leaks using a leak
detector.
6. Tee all high and low ports into one high and one low line and connect
to transmitter or gage.
7. The devices should be checked occassionally for build-up of dirt or
debris common in an HVAC system.
CALIBRATION
Sometimes field calibration may be required if the probe is installed in a
bad location i.e. immediately downstream of an elbow. In order to
calibrate, you must either perform a traverse of the duct or a sum of the
air registers and compare this with the MAFS output. Then, you must
make the correction to the effective area in the computer to make up for
the error.
MAINTENANCE/REPAIR
Upon final installation of the Series MAFS, no routine maintenance is
required. The Series MAFS is not field serviceable and should be
returned if repair is needed. Field repair should not be attempted and
may void warranty.
WARRANTY/RETURN
Refer to “Terms and Conditions of Sales” in our catalog and on our
website. Contact customer service to receive a Return Goods
Authorization number before shipping the product back for repair. Be
sure to include a brief description of the problem plus any additional
application notes.
MAFS
M
A
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