Dwyer Instruments DM DigiMag Series

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Series DM DigiMag

Differential Pressure Transmitter

Specications - Installation and Operating Instructions

Bulletin P-DMT

The Series DM DigiMag

Differential Pressure Transmitter senses the pressure

of air and compatible gases and sends a standard 4-20 mA output signal. The DM

housing is specically designed to mount in the same diameter cutout as a standard

Magnehelic

gage. A wide range of models are available factory calibrated to specic

ranges. The polycarbonate molded housing features integral pressure connections,

which reduces installation time. Digital push-button zero and span simplify calibration

over typical turn-potentiometers. A single push-button allows eld selection of 4 to 6

engineering units, depending on the range.

BENEFITS/FEATURES

• Reduced installation time through zero and span controls that provides quick and

easy calibration

• Fast and easy setup and calibration with push-button zero and span controls

• Immediate corrective action can be taken by local alerts via the easy-to-read LCD

display

• Reduces upgrade installation costs and simplies eld upgrade from a Magnehelic

gage, as both use the same diameter cutout

APPLICATIONS

• Differential pressure across lters

• Fan control

• Static pressures in ducts or buildings

• Room pressurization monitoring

INSTALLATION

Location:

Select a clean, dry mounting location free from excess vibration where the temperature

will remain between -4 to 158°F (-20 to 70°C). Distance from the receiver is limited only

by total loop resistance. See Electrical Connections on the next page. The tubing

supplying pressure to the instrument can be practically any length required, but long

lengths will increase the response time slightly.

Position:

Transmitter pressure accuracy is not affected by orientation. If choosing a non-vertical

installation, ZERO the unit to remove any offset due to gravity.

Pressure Connections:

SPECIFICATIONS

Service: Air and non-combustible, compatible gases.

Wetted Materials: Consult factory.

Housing Material: Polycarbonate.

Accuracy: ±1% FSO for all ranges except 0.25 in w.c. @ ±2% FSO, and ranges at

or below ±0.1 in w.c. @ ±4% FSO.

Stability: < ±1% / year FSO.

Pressure Limits: Ranges > 1 in w.c.: 6 psi max operation, 6 psi burst; Ranges ≤ 1

in w.c.: 3.6 psi max operation, 6 psi burst.

Temperature Limits: -4 to 158°F (-20 to 70°C).

Thermal Effect: 0.036% FS/°C (0.02% FS/°F).

Power Requirements: 10-35 VDC (2-wire).

Output Signal: 4-20 mA (2-wire).

Zero and Span Adjustments: Push-button.

Loop Resistance: 0 to 1250 Ω max.

Current Consumption: 21 mA max.

Electrical Connections: Screw-type terminals.

Process Connections: Male ports on side for 1/8˝, 3/16˝, 1/4˝, 5 mm, 6 mm ID

exible tubing.

Enclosure Rating: NEMA 4X (IP66).

Mounting Orientation: Not sensitive to position.

Size: 5˝ OD (127 mm) x 1.9˝ (48 mm) deep.

Weight: 7.04 oz (200 g).

Agency Approvals: CE.

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone: 219-879-8000

Fax: 219-872-9057

www.dwyer-inst.com

e-mail: info@dwyermail.com

5 [127.00]

1 [25.40]

HIGH PRESSURE POR

LOW PRESSURE PORT

1/2 [12.70]

1-43/64

[42.34]

15/64

[5.84]

Two integral tubing connections are provided on the side of the

gage. They are sized to t 1/8˝, 3/16˝, 1/4˝, 5 mm, and 6 mm ID

exible tubing. Be sure the pressure rating of the tubing exceeds that of the operating

ranges.

NOTICE

Need help?

Do you have a question about the Dwyer Instruments DM DigiMag Series and is the answer not in the manual?

The Dwyer Series DM DigiMag® Differential Pressure Transmitter is a device designed to sense air and compatible gas pressures, converting them into a standard 4-20 mA output signal. Its housing is specifically engineered to fit into the same diameter cutout as a standard Magnehelic® gauge, simplifying upgrades and reducing installation costs.

Function Description:

The transmitter measures differential pressure and provides an analog output signal proportional to the sensed pressure. It features digital push-buttons for zero and span adjustments, which streamline calibration compared to traditional turn-potentiometers. The device also includes an easy-to-read LCD display for local alerts and pressure readings. Depending on the range, a single push-button allows for field selection of 4 to 6 engineering units.

Important Technical Specifications:

Service: Air and non-combustible, compatible gases.
Wetted Materials: Consult factory.
Housing Material: Polycarbonate.
Accuracy:
- ±1% FSO for all ranges except 0.25 in w.c. (@ ±2% FSO).
- Ranges at or below ±0.1 in w.c. (@ ±4% FSO).
Stability: < ±1% / year FSO.
Pressure Limits:
- Ranges > 1 in w.c.: 6 psi max operation, 6 psi burst.
- Ranges ≤ 1 in w.c.: 3.6 psi max operation, 6 psi burst.
Temperature Limits: -4 to 158°F (-20 to 70°C).
Thermal Effect: 0.036% FS/°C (0.02% FS/°F).
Power Requirements: 10-35 VDC (2-wire).
Output Signal: 4-20 mA (2-wire).
Zero and Span Adjustments: Push-button.
Loop Resistance: 0 to 1250 Ω max.
Current Consumption: 21 mA max.
Electrical Connections: Screw-type terminals.
Process Connections: Male ports on side for 1/8", 3/16", 1/4", 5 mm, 6 mm ID flexible tubing.
Enclosure Rating: NEMA 4X (IP66).
Mounting Orientation: Not sensitive to position.
Size: 5" OD (127 mm) x 1.9" (48 mm) deep.
Weight: 7.04 oz (200 g).
Agency Approvals: CE.

Usage Features:

Installation:
- Location: Requires a clean, dry mounting location free from excessive vibration, with temperatures between -4 to 158°F (-20 to 70°C). The distance from the receiver is limited only by total loop resistance. Tubing length is flexible, but long lengths may increase response time.
- Position: Accuracy is not affected by orientation. If not mounted vertically, a ZERO adjustment is recommended to remove any gravitational offset.
- Pressure Connections: Two integral tubing connections are provided, sized for 1/8", 3/16", 1/4", 5 mm, and 6 mm ID flexible tubing. Ensure tubing pressure rating exceeds operating ranges.
- Electrical Connections: Screw-type terminals are provided for power supply and output. The device requires a 10-35 VDC power supply with a minimum current capability of 40 mA DC. Loop resistance should not exceed 1250 Ω.
Calibration:
- Requires a calibrated pressure source, an instrument to validate pressure, and an ammeter to measure current output.
- Preparation: Press both ZERO and UNITS buttons simultaneously for 6+ seconds until "CAL" is displayed. The units indicator will blink for approximately 10 minutes, signaling readiness for calibration.
- Zero Calibration: Apply zero pressure to both ports, press the ZERO button for 3 seconds. The display will show "2Er" before returning to the home display.
- Span Calibration: Apply the maximum desired pressure to the positive "+" port, press and hold the UNITS button for 3 seconds. The display will show "SPA" before returning to the home display. It is recommended to perform zero calibration before span calibration.
- Response Time Calibration: Press both ZERO and UNITS buttons simultaneously for 3 seconds to toggle between fast (0 seconds) and dampened (4 seconds) response. The display will show FST or SLO.
- Restore Factory Calibration: Press both ZERO and UNITS buttons simultaneously for 6 seconds until "rSt" is displayed. The device will reboot after 5-6 seconds.

Maintenance Features:

The Series DM requires no routine maintenance after final installation.
It is not field serviceable and should be returned if repair is needed. Attempting field repair may void the warranty.
The device should be recycled where facilities exist, in accordance with local authority guidelines, as it is considered waste electrical product.