Series-RSM

Supported Applications

The Dwyer Series RSM Room Status Monitor is designed for critical low differential pressure applications requiring stringent monitoring and alarming. The series supports positive or negative pressure monitoring in protected environments, including hospital isolation rooms configured per CDC guidelines.

Operating Conditions & Performance

The Series RSM measures differential pressure with a resolution of 0.001 in w.c. Accuracy is specified as ±0.5% FS, with an optional accuracy class of ±0.25% FS available. The series offers six operating ranges: ±0.05 in w.c., ±0.1 in w.c., ±0.25 in w.c., ±0.5 in w.c., ±1 in w.c., and ±2.5 in w.c.

Performance is maintained within an ambient temperature range of 32 to 120°F (0 to 50°C) and a humidity rating of 5 to 95% relative humidity (non-condensing). The unit utilizes true differential pressure measurement with dead-ended very low-pressure capacitance, avoiding cross-contamination between the room and reference space.

Key Specifications

• Measurement Type: Differential Pressure
• Resolution: 0.001 in w.c.
• Accuracy: ±0.5% FS (standard); ±0.25% FS (optional)
• Burst/Pressure Rating: ±15 in w.c. (±3.7 kPa)
• Media Compatibility: Air or non-conductive, non-explosive gases
• Housing Material: Fire retardant plastic
• Enclosure Rating: NEMA 1 (IP20) for indoor applications

Configuration Options

The Series RSM is a complete system featuring a backlit RGB LCD display with a graphical user interface. This interface provides access to pressure, security, calibration, and alarm setup menus, including password protection levels.

Status Indication & Alarms

• Visual: Red and green LEDs indicate normal room condition or breach in room pressure protection.
• Audible: Local audible alarm with a time delay feature; includes an acknowledge switch to silence the buzzer.

Outputs & Communication

Selectable output signals include 4-20 mA (2-wire), 0-5 VDC (3-wire), and 0-10 VDC (3-wire). The load resistance for the 4-20 mA output is 0 to 510 Ω. Optional BACnet MSTP communication is available.

Power & Connections

• Order Code A: 24 VAC (18 to 32 VAC, 50 to 60 Hz)
• Order Code B: 120 VAC (85 to 265 VAC, 50 to 60 Hz)
• Main Supply Fluctuation Tolerance: Up to 10%
• Electrical Connection: Removable terminal block
• Process Connection: Barbed fittings for 3/16" I.D. tubing

Key Product Differences

The series is configured by model number to define the operating range and excitation/output combination.

• Ranges: Models RSM-1 through RSM-6 correspond to ranges of ±0.05 in w.c., ±0.1 in w.c., ±0.25 in w.c., ±0.5 in w.c., ±1 in w.c., and ±2.5 in w.c.
• Excitation/Output Suffixes:

• Suffix -A: 24 VAC excitation with selectable output (4-20 mA, 0-5 VDC, or 0-10 VDC).
• Suffix -B: 120 VAC excitation with selectable output.
• Optional BACnet communication requires changing the suffix to -C for 24 VAC models and -D for 120 VAC models.

An optional Remote Annunciator (Model A-285) is available, providing a visible/audible alarm with an acknowledge switch. The unit weighs 1.5 lbs (680 g) and measures 8" H x 5.4" W x 1.8" D (20.3 H x 13.7 W x 4.1 D cm).