The Dwyer 605-11 Magnehelic® Differential Pressure Indicating Transmitter is a ±0.25 in WC (approximately ±62 Pa equivalent) bidirectional configuration of the Series 605 platform that combines the time-proven Magnehelic® mechanical dial gage with a 2-wire, 4–20 mA electronic transmitter in a single 4-inch instrument. The 605-11 measures pressure swings in both directions across the ±0.25 in WC span and delivers both a local analog reading and a linear loop signal simultaneously, so a technician walking the equipment room reads the value directly off the dial while the building automation system receives the same measurement — no parallel gage + transmitter pair and no isolation amplifier between the local indicator and the loop.
The 605-11 delivers ±2% FS electrical accuracy and ±3% FS mechanical accuracy. Power for the 605-11 comes from any 10–35 VDC supply through the rear-mounted screw terminal block, and the 605-11 drops into 4-inch panel cutouts originally drilled for a standard Magnehelic® gage — ordering with the optional -SS stainless bezel makes a one-for-one field upgrade without rework, so legacy gage installations get a BAS-compatible signal without a panel re-cut.
Building pressurization monitoring where pressure swings around zero (positive and negative), cleanroom envelope monitoring, isolation room pressure verification, and any HVAC application where directional pressure information matters as much as magnitude.
Key Features
The 605-11 puts a Magnehelic® analog dial and a calibrated 2-wire 4–20 mA transmitter into the same 4-inch instrument, so the 605-11 gives a maintenance technician a direct visual reading while the controller upstairs sees the same measurement as a loop signal.
Inside the 605-11 is the same magnetically-linked diaphragm-and-helix sensing mechanism that has driven the Magnehelic® gage line for decades — quick response and ±1% FS/year stability without recalibration drift.
The 605-11 delivers ±2% FS electrical accuracy on its ±0.25 in WC range — well within the tolerance band for typical HVAC differential-pressure indication and BAS trending.
The 605-11 is a true 2-wire transmitter powered by any 10–35 VDC supply through the rear screw-terminal block, with a maximum 1250 Ω loop resistance — making the 605-11 a drop-in fit for nearly any BAS or PLC current-loop input without isolation amplifiers.
Ordered with the optional -SS brushed-stainless bezel, the 605-11 matches the installation diameter of a standard Magnehelic® gage — existing 4-inch panel cutouts accept the 605-11 directly, so gage-only panels can be upgraded to a 4–20 mA signal point without re-cutting sheet metal.
Zero and span on the 605-11 are set with protected potentiometers driven by a supplied spanner-style key — not exposed knobs — so a verified 605-11 calibration stays put even in shared mechanical rooms with foot traffic.
Technical Specifications
| Specification | Value |
|---|---|
| Manufacturer Part Number | 605-11 |
| Series | Dwyer Series 605 Magnehelic® Indicating Transmitter |
| Pressure Range | ±0.25 in WC (approximately ±62 Pa) |
| Direction | Bidirectional |
| Service | Air and non-combustible, compatible gases |
| Electrical Accuracy | ±2% FS (includes linearity, hysteresis, repeatability) |
| Mechanical Accuracy | ±3% FS |
| Long-Term Stability | ±1% FS/year |
| Maximum Pressure | 10 psi (68.95 kPa) |
| Operating Temperature | 20 to 120 °F (-6.67 to 48.9 °C) |
| Compensated Temperature Range | 32 to 120 °F (0 to 48.9 °C) |
| Thermal Effect | ±0.025% FS/°F (±0.045% FS/°C) |
| Power Requirements | 10–35 VDC (2-wire) |
| Output Signal | 4–20 mA |
| Loop Resistance | 0–1250 Ω max |
| Current Consumption | 38 mA max |
| Zero & Span Adjustment | Protected potentiometers (spanner key supplied) |
| Electrical Connections | Screw terminal block (rear) |
| Process Connections | 1/8 in female NPT (high and low) |
| Mounting | Panel mount or surface mount |
| Mounting Orientation | Diaphragm vertical (required for stated accuracy) |
| Dial Face Size | 4 in (101.6 mm) |
| Outside Diameter | 5 in (127 mm); 4-3/4 in (120.7 mm) with -SS bezel |
| Depth | 2-11/16 in (68.3 mm); 2-21/32 in (67.5 mm) with -SS bezel |
| Weight | 1 lb 12.6 oz (811 g) |
| Compliance | CE |
| Options Available | -SS (304 brushed stainless steel bezel), -NIST (traceable calibration certificate) |
What’s In the Box
- Dwyer Series 605 Magnehelic® indicating transmitter (605-11)
- Mounting ring and split snap ring for panel mounting
- (4) 6-32 x 1-1/4 in screws for panel mounting
- (3) 6-32 x 5/16 in screws for surface mounting
- (2) Tubing-to-1/8 in NPT adapters
- (2) 1/8 in NPT pipe plugs (for unused pressure ports)
- Spanner-style adjustment key (for protected zero/span potentiometers)
Documentation
Frequently Asked Questions
The 605-11 is a bidirectional indicating transmitter with a ±0.25 in WC range. Both the analog dial and the 4–20 mA loop scale linearly across the full bidirectional span, with the loop signal centered at the midpoint of the range.
For the rated accuracy, yes — the 605-11 is factory-calibrated with the diaphragm in the vertical position and should be installed face-vertical. Non-vertical orientation will shift the zero and degrade the published accuracy of the 605-11; consult Dwyer if a non-standard orientation is required.
The 605-11 outputs a 2-wire 4–20 mA current signal linearly proportional to the ±0.25 in WC range, with 4 mA at zero (or the negative end on bidirectional models) and 20 mA at full scale. Maximum loop resistance is 1250 Ω at 35 VDC.
Yes — ordering the 605-11 with the optional -SS (304 brushed stainless steel) bezel makes the installation diameter compatible with the standard Magnehelic® gage cutout, so an existing 4-inch panel hole accepts the 605-11 directly. This is the intended field-upgrade path for gage-only panels that need to feed a 4–20 mA loop to the BAS.
Any 10–35 VDC supply with at least 40 mA capacity per 605-11. The 605-11 is a 2-wire transmitter and is not designed for AC voltage operation — applying AC will cause permanent damage not covered by warranty.
Yes — a single DC supply can power several 605-11 transmitters in parallel as long as the supply has enough current. Minimum required current is the number of 605-11 units multiplied by 20 mA.
Yes — insert a 250 Ω resistor (commonly 249 Ω 1/2 W ±1% metal film) in series with the 605-11 current loop, in parallel with the receiver input at the panel end. The voltage drop across that resistor converts the 4–20 mA loop into a 1–5 V input.
The 605-11 ships factory-calibrated for 4 mA at zero and 20 mA at full scale. To re-verify: insert a milliammeter in series with the loop, vent both ports and set the dial zero with the slotted screw at center-bottom, apply 0.25 in WC (positive) to the HI port, and use the supplied spanner key on the protected SPAN potentiometer for 20 mA then on ZERO for 4 mA. The two controls are slightly interactive on the 605-11 — iterate two or three times.
- Brand:
- Dwyer
- Series:
- 605 Magnehelic
- Product Type:
- Indicating Transmitter
- Pressure Range Class:
- Bidirectional Symmetric
- Pressure Range:
- +/-0.25 in WC
- Direction:
- Bidirectional
- Output Signal:
- 4-20 mA
- Display:
- Analog Dial
- Accuracy Class:
- Mid (0.5 to 2% FS)
- Mounting:
- Panel/Surface
- Probe:
- No Probe
