The Dwyer 2001-SP is a 4 in dial differential pressure gage with a 0-1.0 in w.c. range, 2% of full scale accuracy and 1/8 in female NPT duplicate high and low pressure taps.
It uses Dwyer's frictionless Magnehelic movement: a silicone rubber diaphragm drives a flat spring-steel range spring carrying a samarium cobalt magnet, which rotates a helix in jeweled bearings to move the pointer with no mechanical linkages. The gage needs no external power and no manometer fluid. It indicates positive, negative (vacuum) or differential pressure of air and non-combustible, compatible gases.
Power note. The gage movement is mechanical and needs no supply voltage. The -SP LED set point indicator fitted to this model does require a 12-24 VDC supply.
Features
- Frictionless magnetic movement A samarium cobalt magnet rotates the helix without mechanical linkages, so the design resists shock, vibration and over-pressures.
- Reads at a distance A precision litho-printed scale behind an undistorted clear acrylic cover, with a red-tipped heat treated aluminium pointer rigidly mounted on the helix shaft.
- Weatherproof housing IP67 die cast aluminium case and bezel, iridite-dipped and finished in baked dark grey hammerloid to withstand a 168 hour salt spray corrosion test.
- Zero without opening the gage The zero adjustment screw sits in the cover and is reached without removing it; an O-ring seal maintains pressure tightness.
- Surface or flush mount One case size covers all standard pressure options. Dwyer publishes conflicting central panel openings for set point indicator models, so check Panel Cutout under Specifications and confirm the layout before cutting a panel.
- No manometer fluid The Magnehelic movement is dry, so there is no indicating fluid to service.
- Option -SP: LED Set Point Indicator This model ships with a bright red LED set point indicator on the right of the scale, field adjustable from the gage face and powered from 12-24 VDC.
Applications
- Filter monitoring
- Air velocity with a Dwyer pitot tube
- Blower vacuum monitoring
- Fan pressure indication
- Duct, room or building pressures
- Clean room positive pressure indication
- Filter status monitoring in air handler units
- Filter monitoring in dust collectors
- Pressure monitoring of scrubber and fume exhaust systems
- Room pressure monitoring for hospital isolation rooms
Applications listed are those published by Dwyer for the Series 2000, in the catalog page and the Series 2000 product flyer. Dwyer specifies service for air and non-combustible, compatible gases.
Specifications
| Model / Part Number | 2001-SP |
|---|---|
| Range | 0-1.0 in w.c. |
| Dial Face | 4 in (101.6 mm) diameter |
| Minor Divisions | .02 |
| Accuracy | +/-2% of full scale throughout range at 70 F (21.1 C). The -HA high accuracy option improves this to +/-1% of full scale for this range. |
| Scale Position | Standard calibration; diaphragm in vertical position. |
| Service | Air and non-combustible, compatible gases. Natural gas option available. May be used with hydrogen when ordered with a Buna-N diaphragm at pressures below 35 psi. |
| Media Compatibility | Air and non-combustible, compatible gases. Consult factory to confirm compatibility with a specific gas before ordering. |
| Wetted Materials | Consult factory. |
| Housing | Die cast aluminium case and bezel with a clear acrylic cover. Exterior finish coated grey to withstand a 168 hour salt spray corrosion test. |
| Cover and Bezel | The set point indicator option requires an MP or HP style cover and bezel (Series 2000-SP datasheet). |
| Total Pressure Limit | 35 psig (2.41 bar); HP option 80 psig (5.52 bar) |
| Overpressure | Dwyer publishes the relief plug as opening at approximately 25 psig (1.72 bar) on standard gages only, and separately states that no blowout plug is used on medium or high pressure models. Because the set point indicator option requires an MP or HP style cover and bezel, ZOT Supply has not been able to establish from published documentation whether a relief plug is fitted to this configuration. Do not rely on a relief plug on this model. Contact us or DwyerOmega if overpressure venting matters to your application. |
| Enclosure Rating | IP67 |
| Temperature Limits | 20 F (-6.67 C) to 140 F (60 C) |
| Dial Size | 4 in (101.6 mm) diameter dial face |
| Mounting Orientation | Diaphragm in vertical position. Consult factory for other orientations. |
| Panel Cutout (flush mount) | Dwyer publishes two conflicting central panel openings for set point indicator models: 4-13/16 in in the Series 2000 catalog note for -SP, and 4-3/4 in (120 mm) in Bulletin A-27 for the MP and HP cover and bezel style this option requires. Separately, and not as a third opening, the Series 2000-SP datasheet specifies the mounting hole pattern as four 6-32 holes on a 5-1/8 in bolt circle with a 5 in outside diameter bezel and a 5-1/2 in outside diameter mounting ring; it gives no central hole diameter at all. Confirm the layout for your exact part with DwyerOmega before cutting a panel. |
| Process Connections | 1/8 in female NPT duplicate high and low pressure taps, one pair side and one pair back. |
| Weight | 1 lb 2 oz (510 g) |
| Standard Accessories | Two 1/8 in NPT plugs for duplicate pressure taps, two 1/8 in pipe thread to rubber tubing adapters and three flush mounting adapters with screws. |
| RoHS Compliance | DwyerOmega issues a per-part Certificate of Compliance for EU Directive 2011/65/EU and 2015/863 covering this exact part number, with RoHS 2015/863 status Compliant (certificate retrieved 13 August 2026). This supersedes the legacy Series 2000 catalog note that -SP models are not RoHS approved. Pull a current copy using the link in Documentation before submitting compliance paperwork. |
| Design Origin | Designed in the USA using high quality components (Series 2000 product flyer). Dwyer does not publish a country of manufacture for this series, so no country of origin is claimed here. |
| Warranty | 5 Year Limited Warranty |
For applications with a high cycle rate within the gage total pressure rating, Dwyer recommends selecting the next higher pressure rating. See the medium (-MP) and high (-HP) pressure options.
Ordering Options
| -HA | High accuracy. Dwyer states +/-1% of full scale on standard +/-2% ranges, +/-1.5% on the -0, -100PA, -125PA and -10MM ranges, and +/-2% on the -00, -60PA and -6MM ranges. For this model the -HA figure is +/-1% of full scale. Includes a mirrored scale overlay and a six point calibration certificate. |
|---|---|
| -HP | High pressure, for pressures to 80 psig. |
| -LT | Low temperature, to -20 F (-28 C). |
| -ASF | Adjustable signal flag, integral with the plastic gage cover. Not available on medium or high pressure construction. |
| -SS / -SB / -CB | Brushed 304 stainless, electropolished 304 stainless, or chrome plated bezel. |
| -M | Mirrored scale overlay, reduces parallax error. |
| -G / -R / -Y | Green, red or yellow transparent scale overlay. |
| -AHU1 / -AHU2 | Attached surface mounting plate; -AHU2 adds the A-481 installer kit. |
| -FC / -NIST | Factory calibration certificate, or NIST traceable calibration certificate. |
These are options published for the Series 2000 family. Not every option combines with every model or with the configuration on this page. Contact ZOT Supply to confirm a configured part number before ordering.
Accessories
| A-610 | Pipe mounting kit for 1-1/4 in to 2 in horizontal or vertical pipe. |
|---|---|
| A-605 / A-605B / A-605C | Air filter gage kits with static pressure tips, tubing and vent valves. |
| A-310A | 3-way vent valves, for permanently connected installations. |
| A-321 | Brass safety relief valve, opens at 10 psi. (DwyerOmega accessory listing.) |
| A-300 / A-368 / A-369 | Flush mounting bracket, surface mounting plate, stand-hang bracket. |
| A-464 / A-464-SS | Flush mount kit, steel or stainless steel. |
| A-286 | Gage panel mounting flange. |
| A-135 | Rubber gasket for panel mounting. |
| A-432 / A-401 | Portable carrying kit and plastic carry case. |
| A-448 | 3-piece magnet kit for mounting directly to a magnetic surface. |
| A-320 Series | Instrument enclosures in ABS or 304 stainless steel. |
A-610 pipe size is stated as 1-1/4 in to 2 in on the current Series 2000 catalog page and in Bulletin A-27. The superseded A-610 sheet (Bulletin A-38, 1989) states 1-1/2 in to 2 in. The current figure is used here.
Frequently Asked Questions
What is the pressure range of the Dwyer 2001-SP?
The Dwyer 2001-SP is a standard Magnehelic differential pressure gage with a 0-1.0 in w.c. range and +/-2% of full scale accuracy at 70 F (21.1 C).
Does the Dwyer 2001-SP need power or wiring?
The gage movement itself is mechanical and needs no power. The -SP LED set point indicator on this model does require a 12-24 VDC supply.
What is the maximum pressure the Dwyer 2001-SP can take?
The total pressure limit is 35 psig (2.41 bar); HP option 80 psig (5.52 bar). Dwyer documentation does not establish whether a relief plug is fitted to the set point indicator configuration, so do not rely on one. Engineer the system not to exceed the rating.
What media can the Dwyer 2001-SP be used with?
Dwyer specifies air and non-combustible, compatible gases. A natural gas option is available, and the gage may be used with hydrogen when ordered with a Buna-N diaphragm at pressures below 35 psi.
What panel opening does the Dwyer 2001-SP need for flush mounting?
Dwyer publishes two conflicting central openings: 4-13/16 in in the Series 2000 catalog and 4-3/4 in (120 mm) in Bulletin A-27 for the MP and HP cover and bezel style this option requires. The Series 2000-SP datasheet gives no central hole diameter; it specifies the mounting hole pattern as four 6-32 holes on a 5-1/8 in bolt circle. Confirm the layout with DwyerOmega before cutting a panel.
Is the Dwyer 2001-SP RoHS compliant?
Yes. DwyerOmega issues a Certificate of Compliance for this exact part number showing RoHS 2015/863 status Compliant. That certificate supersedes the older catalog note about -SP models. A live link to it is in the Documentation section.
Documentation
- Series 2000 Catalog Page (specifications and model chart)
- Bulletin A-27 - Installation and Operating Instructions
- Bulletin A-27-HP-MP - Medium and High Pressure Option
- Bulletin A-28 - Air Filter Gage Instructions
- Bulletin A-38 - A-610 Pipe Mounting Kit Instructions
- Series 2000 Magnehelic Product Flyer
- Series 2000-SP Datasheet (set point indicator models)
- RoHS Certificate of Compliance for 2001-SP (live, issued by DwyerOmega)
Specification source. Range and accuracy for the 2001-SP are taken from the Dwyer Series 2000 catalog page (2000_1.pdf). Construction, pressure, temperature and mounting data are from the Series 2000-SP datasheet (2000-SP_cat.pdf), which is the model-specific source for set point indicator models and supersedes the general Series 2000 catalog where the two differ. Note that Dwyer publishes conflicting flush-mount arrangements for -SP; see the Panel Cutout row. RoHS status is not taken from the catalog. It is sourced separately from the DwyerOmega per-part compliance-status lookup, linked above. Data verified August 2026.
WARNING (California Proposition 65): This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
- Pressure Type:
- Differential Pressure
- Series:
- 2000 Magnehelic
- Range Units:
- Inches of Water
- Full Scale Range:
- 0-1.0 in w.c.
- Scale Type:
- Standard
- Accuracy:
- +/-2% FS
- Option:
- LED Set Point Indicator
- Process Connection:
- 1/8 in Female NPT
- Enclosure Rating:
- IP67
- Dial Size:
- 4 in
- Scale Position:
- Standard
