Overview
The Series DM-1200 DigiMag replaces an analog mechanical gage with a field-programmable digital instrument that can be set for pressure, air velocity or volumetric flow, so one device covers several applications. All models are factory calibrated to a specific range, and the 4-digit LCD displays readings in common English and metric units so no manual conversion is needed.
Four menus reached from the MENU key give access to security level, engineering units, K-factor for pitot tubes and flow sensors, circular or rectangular duct dimensions for volumetric flow, filter set point, peak and valley readings, digital damping, display update rate, and zero and span field calibration.
A filter set point can be entered so the display blinks when the reading crosses it, alerting the user that a maintenance action needs to occur. Power is flexible: the gage runs on 9-24 VDC line power or a 9V battery, and when both are connected the battery acts as backup if line power is lost or interrupted.
Specifications
| Model | DM-1205 |
| Range | 0 to 2 in w.c. |
| Resolution | 0.001 in w.c. |
| Service | Air and non-combustible, compatible gases. |
| Wetted Materials | Consult factory. |
| Housing Materials | Glass filled plastic. |
| Accuracy | +/-1% F.S. including linearity, hysteresis and repeatability. |
| Long Term Stability | +/-1% F.S. per year. |
| Thermal Effect | +/-0.05% F.S./F typical. |
| Temperature Limits | 0 to 140 F (-18 to 60 C). |
| Compensated Temperature Limits | 32 to 122 F (0 to 50 C). |
| Pressure Limit | 2 psi (13.7 kPa) |
| Display | 4-digit LCD, digits 0.60 in H x 0.33 in W. |
| Display Update | Selectable from 1 second to 10 minutes, or update only on button push. |
| Selectable Engineering Units | in w.c., psi, kPa, Pa, mm w.c., mBar, in Hg, mm Hg, and % of full scale (0-100%). |
| Digital Damping | Adjustable 1 to 15. |
| Velocity Units | SFPM or m/s. |
| Flow Units | SCFM or cubic meters per hour. |
| K-Factor Range | 0.01 to 2.00, factory set to 1.00. |
| Power Requirements | 9V battery or external power supply 9-24 VDC. Battery included, shipped not connected. |
| Type of Battery | 9V alkaline (Duracell PC 1604 or equivalent). |
| Battery Service Life | 150 hours typical at 1 second display update; 9 months typical at 10 minute display update; 1.5 years typical with display update disabled. Up to four times longer with a lithium ULTRALIFE U9VL-J. |
| Current Consumption | 5 mA maximum. |
| Electrical Connections | Removable terminal block for 16 to 26 AWG. |
| Electrical Entry | Cable gland for 0.114 to 0.250 in (2.9 to 6.4 mm) diameter cable. |
| Process Connections | 1/8 in (3 mm) ID tubing. |
| Tubing Size | 3/16 in (4.8 mm) I.D. x 5/16 in (7.9 mm) O.D. flexible PVC tubing. |
| Panel Cut-Out | 4-9/16 in diameter panel opening; vertical mounting position required. |
| Enclosure Rating | NEMA 4X (IP66). |
| Size | 5 in (127 mm) O.D. front face; 2.33 in overall depth (dimensional drawing). |
| Weight | 1.18 lb (535 g). |
| Agency Approvals | CE; EN 61326-1 [Immunity Test Requirement for Industrial Environments] to IEC 61000-3-2, 61000-3-3, 61000-4-2, 61000-4-3, 61000-4-4, 61000-4-5, 61000-4-6 and 61000-4-11. |
Range in Selectable Engineering Units
| in w.c. | Pa | kPa | mbar | mm w.c. | mm Hg |
|---|---|---|---|---|---|
| 2.000 | 498.2 | 0.498 | 4.982 | 50.80 | 3.736 |
Full-scale value of this model expressed in each selectable engineering unit. Units marked with a dash on the Dwyer model chart are not offered for this range and are omitted.
Air Velocity and Flow
| Velocity Range (English) | 0 to 5663 SFPM |
| Velocity Range (Metric) | 0 to 28.77 m/s |
| Max Duct Size, Flow Range LO | 1.766 sq ft (0.096 sq m) |
| Max Duct Size, Flow Range MED | 17.66 sq ft (0.965 sq m) |
| Max Duct Size, Flow Range HI | 176.6 sq ft (9.654 sq m) |
Air velocity and flow readings assume standard dry air at 70 F and 29.92 in Hg barometric pressure. Flow range LO reads to 9999, MED to 99.99 x 1K and HI to 999.9 x 1K in the selected flow unit.
Applications
- Differential pressure across filters
- Fan control
- Static pressure in ducts or buildings
- Room pressurization monitoring
- Air velocity traverses with a pitot tube
- Volumetric air flow in round or rectangular duct
In the Box
- Mounting lugs - 3
- 6-20 x 2-1/2 in screws - 3
- 4-20 x 3/8 in screws - 3
- Cable gland - 1
- 9V alkaline battery - 1 (shipped not connected)
Optional Accessories
| A-286 | 4-1/2 in gage panel mounting flange |
| A-300 | Flat flush mounting bracket |
| A-480 | Plastic static pressure tip |
| A-489 | 4 in straight static pressure tip with flange |
Add the -NIST suffix when ordering for a NIST traceable calibration certificate (example: DM-1205-NIST).
Documentation
- Dwyer Series DM-1000 DigiMag Datasheet
- Dwyer Series DM-1200 Installation and Operating Instructions (Bulletin P-DM-1200)
Frequently Asked Questions
What is the pressure range of the Dwyer DM-1205?
The DM-1205 covers 0 to 2 in w.c. (0 to 498.2 Pa), with 0.001 in w.c. resolution.
Can the Dwyer DM-1205 measure air velocity and flow?
Yes. The DM-1200 can be field set for pressure, air velocity or volumetric flow. On this range it reads velocity to 0 to 5663 SFPM (0 to 28.77 m/s), and a K-factor from 0.01 to 2.00 can be entered for the pitot tube or flow sensor in use.
How accurate is the Dwyer DM-1205?
It is rated +/-1% F.S. including linearity, hysteresis and repeatability. Dwyer specifies +/-1% F.S. on ranges down to 2 in w.c. and +/-2% F.S. on the 1, 0.5 and 0.25 in w.c. ranges.
What units can the Dwyer DM-1205 display?
Eight engineering units plus percent of full scale: in w.c., psi, kPa, Pa, mm w.c., mBar, in Hg and mm Hg. Units are changed in the field from the OPEr menu, so no conversion arithmetic is needed.
How is the Dwyer DM-1205 powered?
A 9V alkaline battery or an external 9-24 VDC supply. The battery is included but shipped not connected. If both are connected the battery acts as backup when line power is lost.
How long does the battery last?
About 150 hours at a 1 second display update, about 9 months at a 10 minute update, and about 1.5 years with the display update disabled. A lithium ULTRALIFE U9VL-J can extend that up to four times.
Does the Dwyer DM-1205 fit a Magnehelic gage cut-out?
Yes. The gage is a 5 in O.D. front face and installs in a 4-9/16 in diameter panel opening, the same cut-out used by the analog Magnehelic gage. A vertical mounting position is required because that is the position the gage is calibrated in at the factory.
Can the Dwyer DM-1205 alert on a dirty filter?
Yes. A filter set point can be entered and the filter type set to HIGH or LOW, and the display blinks when the reading passes that set point. In 10 minute or on-touch display modes the LCD shows ALAr instead.
Specifications on this page are taken from Dwyer Series DM-1000 catalog page 25 and from Bulletin P-DM-1200, FR# 443779-50 Rev. 4 (2/19). Note also that the DM-1200 bulletin states battery service life as 9 months and 1.5 years in its specification panel but as 1 year and 2 years in its notes section; the specification-panel figures are used above. One discrepancy is unresolved in Dwyer's own literature: the specification panel lists process connections as 1/8 in (3 mm) ID tubing, while the installation section states the integral connections are sized for 3/16 in (4.8 mm) I.D. x 5/16 in (7.9 mm) O.D. flexible PVC tubing. Both figures are shown above as printed; confirm with Dwyer before specifying tubing. Reviewed August 2026.
- Series:
- DM-1000 DigiMag
- Model Family:
- DM-1200
- Measurement Type:
- Differential Pressure
- Measurement Type:
- Air Velocity
- Measurement Type:
- Air Flow
- Pressure Range:
- 0 to 2 in w.c.
- Accuracy:
- +/-1% F.S.
- Display:
- 4-Digit LCD
- Enclosure Rating:
- NEMA 4X IP66
- Power Source:
- 9V Battery or 9-24 VDC
- Process Connection:
- Integral Tubing Ports
