Dwyer Instruments 477AV Operating Manual

Series 477AV Handheld Digital Manometer

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BARBED FOR
1/8 OR 3/16
ID TUBING

Specifications - Installation and Operating Instructions

Bulletin TE-477AV-1

he Series 477AV Handheld Digital Manometer is available with pressure, flow, and

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elocity measurements along with a number of other features. The 477AV uses a highly

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ccurate differential pressure sensor to offer ± 0.5% full scale accuracy. It displays

a
negative, positive, and differential pressure. For pressure, flow, and velocity there are
selectable English and metric units, as seen in the model chart below. The built-in air
velocity and volumetric flow calculations conserve time associated with cumbersome
manual calculations. Additionally, up to 40 readings can be saved—perfect for HVAC
technicians making Pitot tube traverses of airflow readings across a duct. The accuracy
that the 477AV Series provides is critical to maintenance personnel and technicians
who require a highly accurate standard to check their instrumentation or equipment, to
ensure proper performance.

The digital display offers a backlight feature for easier viewing in darker areas.
Meanwhile, battery conservation is monitored and displayed in the event of low battery
condition. The digital manometer will automatically shut off after 20 minutes to prevent
battery drain. This shut-off time can be reduced or disabled if desired. Series 477AV
can be field-calibrated by setting zero & span values. Furthermore, the damping feature
compensates for the fluctuating readings by averaging input values to display a more
stable readout. Included is an audible and visual alarm to warn over flow, over pressure
or over velocity.

Model
477AV-000
477AV-00
477AV-0
477AV-1
477AV-2
477AV-3
477AV-4
477AV-5
477AV-6
477AV-7
477AV-8

Displaying Pressure, Velocity, and Flow

The instrument measures pressure using a piezoelectric sensor. When the 477AV
is powered on the pressure value and the unit of measurement will be shown. If
you select the velocity or flow mode, then velocity or flow will be displayed instead.
The mode selection will persist even after the instrument is turned off. In velocity
and flow modes, if the reading exceeds 9,999, then a “K” will be displayed next to
the unit of measurement and the display will read in units of 1,000 times the original
unit of measurement.

Pressure Range

0-1.000 in w.c.
0-4.000 in w.c.
0-10.00 in w.c.
0-20.00 in w.c.
0-40.00 in w.c.
0-200.0 in w.c.
0-10.00 psi
0-20.00 psi
0-30.00 psi
0-100.0 psi
0-150.0 psi

Velocity Range
fpm

0-4004
0-8009
0-1.266k
0-1.791k
0-1.791k
0-56.63k
0-66.62k
0-94.22k
0-115.4k
0-210.7k
0-258.0k

Available Pressure Units

m/s

20.34

40.69

64.33

90.97

128.7

287.7

338.4

478.6

586.2
1070
1311

psi

0.1445

0.3613

0.7225

1.445

7.225

10.00

20.00

30.00

100.0

150.0

in Hg

0.0736

0.2942

0.7355

1.471

2.942

14.71

20.36

40.72

61.08

203.6

305.4

kPa

0.2491

0.996

2.491

4.982

9.96

49.82

68.95

137.9

206.9

689.5
1034

in w.c.

1.000

4.000

10.00

20.00

40.00

200.0

276.8

553.6

830.4
2768
4152

mm Hg

1.868

7.473

18.68

37.36

74.73

373.6

517.1
1034
1551
5171
7757

SPECIFICATIONS
Service: Air and compatible gases.
Wetted Materials: Consult factory.

ccuracy: ±0.5% FS, 60 to 78°F

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(15.6 to 25.6°C); ±1.5% FS from 32 to
60°F and 78 to 104°F (0 to 15.6°C
and 25.6 to 40.0°C).
Pressure Hysteresis: ±0.1% of full­scale.

Pressure Limits: See chart.
Temperature Limits: 0 to 140°F

(-17.8 to 60°C).

Compensated Temperature Limits:

32 to 104°F (0 to 40°C).
Storage Temperature Limits: -4 to
176°F (-20 to 80°C).

Display: 0.42˝ (10.6 mm) 4 digit LCD.
Resolution: See chart.

mbar

2.491

9.96

24.91

49.82

99.6

498.2

689.5
1379
2069
6895

mm w.c.

25.40

101.6

254.0

508.0
1016
5080
7031

Pa

249.1
996
2491
4982
9964

ft w.c.

0.0833

0.3333

0.8333

1.667

3.333

16.67

13.07

46.13

69.20

230.7

346.0

oz/in

0.5780

2.312

5.780

11.56

23.12

115.6

160.0

320.0

480.0
1600
2400

Units of Pressure: in w.c., ft. w.c., in
Hg, psi, oz/in
Hg, mbar, Pa, kPa, hPa.

nits of Velocity: fpm, fps, mph, m/h,

U

m/s, k/h, knot.

Units of Flow: cfm, m3/h, m3/s.
Power Requirements: 9 V Alkaline

battery, installed non-functional, user
replaceable.

Weight: 10.2 oz (289 g).
Process Connections: Two barbed

connections for use with 1/8˝ (3.18
mm) or 3/16˝ (4.76 mm) ID tubing.
Two compression fittings for use with
1/8˝ (3.18 mm) ID x 1/4˝ (6.35 mm)
OD tubing for 477AV-7 and 477AV-8
only.

Agency Approvals: CE.

2

hPa

cm w.c.

2.491

2.540

9.964

10.16

24.91

25.40

49.82

50.80

99.64

101.6

498.2

508.0

689.5

703.1

1379

1406

2068

2109

6895

7031

2

, mm w.c., cm w.c., mm

Maximum
Pressure

5 psig
5 psig
5 psig
10 psig
10 psig
30 psig
30 psig
60 psig
60 psig
150 psig
200 psig

DWYER INSTRUMENTS, INC.

Phone: [phone] www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [e-mail]

attery Installation

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he unit is shipped with a 9 volt alkaline battery which must be installed before

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peration. When battery replacement becomes necessary, use only a 9 volt

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lkaline type such as Duracell

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®

N1604, Eveready

M

®

22 or equivalent. Zinc-carbon

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types, often labeled heavy-duty are not recommended because of the increased
potential for leakage. Alkaline batteries also offer a better value since they last up
to three times longer in this device. To install the batteries:

. Remove the two screws holding the bottom end-cap (marked BATTERY) in

1

lace.

p

. Connect the battery to the enclosed battery clip observing correct polarity. Be

2

areful not to trap wires between the battery, case, or foam pads which retain

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the battery. This could make it difficult to install the battery or remove it later for
replacement.

3. Be sure the rubber gasket is properly seated in the gasket channel of the end-

ap. Notice that the end-cap will only fit one way because the holes are slightly

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ff center.

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. Place the “z” shaped wrist strap clip in one of the screw recesses and tighten

4

the screws. Do not over-tighten.

5. Attach wrist strap to the clip.

n/Off Power

O

ressing and holding the ON/OFF button will turn the unit on or off.

P

eroing Readings

Z

he 477AV is calibrated at the factory, but users are recommended to zero the

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nstrument before each use. To set a new zero point, press and hold the ZERO

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utton with both ports vented to atmospheric pressure. This setting can be cleared

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only by a factory default.

Display Backlight

The 477AV has a display backlight to be used in the dark or in poor lighting
conditions. It can be turned on or off by pressing and holding the MENU and

NTER buttons at the same time. The backlight setting is not saved after the

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77AV is turned off.

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isplay Hold

D

To hold or freeze a value, press and hold down the HOLD button. When the Hold
function is enabled, the pressure/velocity/flow reading will not change, and the unit
of measure will toggle with the word “HOLD”. If the Store function is used when
Hold is enabled, the reading on the display (not the actual reading) will be stored.
This function cannot be used when a menu is being displayed.

Figure. 1

Pressure Connectors

The 477AV has two barbed connector ports for use with 1/8˝ (3.18 mm) or 3/16˝
(4.76 mm) I.D. tubing.

• For a single positive pressure, remove the end caps from the connectors and

connect the tubing to the port marked “+” and vent the opposite port to
atmosphere.

• For a single negative pressure (vacuum), connect the tubing to port marked “–”

and vent the opposite port to atmosphere.

• To measure differential pressure, connect higher pressure to port marked “+” and

lower pressure to port marked “-”. Manometer will indicate the difference between
the two ports. Velocity and volumetric flow can be found similarly if that is the
current mode.

Buttons and Menus
The 477AV's menu is controlled with four buttons labeled MENU, UP, DOWN, and
ENTER. The buttons are shown in Figure 2.

Figure. 2

477AV Manometer

Storing Readings

Pressing and holding the STORE button will store a reading in the memory. The
display will flash “MEM” and the reading's memory location (e.g. “MEM” and “5”).
The 477AV has the ability to store up to 40 readings in the memory. Readings that
are saved will remain in memory even if the unit is powered off. If the Hold function
is enabled, then the stored value will be the value on the display (not the actual
reading).

Measurement Mode

The 477AV can be set to display pressure, velocity, or volumetric flow. The mode
can be changed by pressing and holding the HOLD and STORE buttons
simultaneously. Once a mode is selected, the menu will continue to prompt for unit
of measurement, K-factor, duct shape and duct size when applicable. Duct size and
shape are input in inches or centimeters, depending on whether the primary unit of
measure is metric or English. Settings for all modes are retained in the memory
even if the mode is changed or the 477AV is turned off.

The mode cannot be changed if there are readings saved in memory, or if the Hold
feature is on. (This prevents a user from accidentally saving readings with different
units of measure.) If a user tries to access the mode submenu when readings are
saved, the display will flash “ERR Log”. If a user tries to access the mode submenu
when the Hold feature is active, the display will flash “ERR Hold”.

1. Press and hold the UP and DOWN arrows simultaneously.

2. Using the UP and DOWN arrows, find the mode (velocity, pressure, or flow) you
want.

3. Press ENTER to confirm the desired mode.

4. The display will prompt for units of measurement. Scroll through the options
with the UP and DOWN arrows until the unit of choice is found.

5. Press ENTER.