About Dwyer 3100MRS Photohelic Switch/Gauge 0 to 100 inch
Dwyer 3100MRS Photohelic Switch/Gauge 0 to 100 inch
Series 3000MR/3000MRS Photohelic® Switch/Gage
Combines Differential Pressure Gage with Low/High Set-Points,Compact Size
| Model | Description |
| 3100MRS-100 inch | Pressure Switch/Gage,Range 0-100 inch, 2.0 minor divisions. |
Includes
- mounting ring, snap ring
- 18" cable assembly
- (2) 3/16" tubing to 1/8" NPT adapters
- (2) 1/8" NPT pipe plugs
- (4) 6-32 x 1-1/4" RH machine screws (panel mounting)
- (3) 6-32 x 5/16" RH machine screws (surface mounting)
he Series 3000MR Photohelic® Switch/Gage combine the functions of a precise, highly repeatable differential pressure switch with a large easy-to-read analog pressure gage employing the durable, time-proven Magnehelic® gage design. Switch setting is easy to adjust with large external knobs on the gage face. Gage reading is unaffected by switch operation - will indicate accurately even if power is interrupted. Solid state design now results in greatly reduced size and weight. Units can be flush mounted in 4-13/16" hole or surface mounted with hardware supplied. 3000MR models employ versatile electromechanical relays with gold over silver contacts - ideal for dry circuits.
Gage accuracy is ±2% of full scale and switch repeatability is ±1%. Switch deadband is one pointer width - less than 1% of full scale. Compatible with air and other non-combustible, non-corrosive gases, they can be used in systems with pressures to 25 psig.
Applications
- Fan Control
- Damper Control
- Environmental Pollution Control
Approvals
- CE Approval
- GOST-R Certificate
Specification
| Service | Air and non-combustible, compatible gases |
| Accuracy | ±2% of FS at 70°F |
| Pressure Limits | -20" Hg to 25 psig |
| Temperature Limits | 20 to 120°F |
| Process Connections | 1/8 female NPT (duplicated side and back) |
| Size | 4" dial face, 5" O.D. x 3-1/8" |
| Weight | 1.8 lb |
| Switch Specifications | |
| Switch Type | Each setpoint has 1 Form C relay (SPDT) |
| Relay Contacts | (resistive load) 1 Form C rated 1.0A @ 30 VDC, 0.3A @ 110 VDC or 0.5A @ 125 VAC. Gold over clad silver - suitable for dry circuits |
| Electrical Connections | 18" cable assembly with 8 conductors |
| Power Requirements | 24 VDC, regulated ±10% |
| Mounting Orientation | Diaphragm in vertical position |
| Set Point Adjustment | Adjustable knobs on face |
| Agency Approvals | CE
|
Reliable Differential Pressure MonitoringThe 3100MRS provides exceptional measurement accuracy (2% FS) and repeatable results (1% FS), making it ideal for process control in HVAC systems, cleanrooms, or filtration setups. Its diaphragm-based sensor ensures accurate readings while the analog dial offers instantaneous visibility. This model supports both visual monitoring and electrical switching within a rugged industrial-grade enclosure.
Versatile Mounting and Durable DesignEngineered for practical installation, the gauge suits both flush and surface mounting orientations. Its die-cast aluminum case, polycarbonate window, and matte grey enamel finish deliver robust resistance to challenging environments. The NEMA 1 (IP20) enclosure limits dust ingress but is best used indoors. Supplied with necessary hardware and an instruction manual, implementation is straightforward across many industrial applications.
FAQs of Dwyer 3100MRS Photohelic Switch/Gauge 0 to 100 inch:
Q: How is the Dwyer 3100MRS Photohelic Switch/Gauge typically used in an industrial setting?
A: This gauge is employed to measure and control differential pressure for air or compatible gases, making it suitable for monitoring HVAC systems, filters, or cleanroom environments. Its integrated snap-action switch enables automatic or remote control of alarms, fans, or other equipment based on pre-set pressure thresholds.
Q: What is the process for installing the Dwyer 3100MRS, and what mounting options are available?
A: Installation is facilitated by the included mounting hardware and instruction manual. The device can be mounted either flush or on a surface, with vertical orientation recommended for optimal performance. The unit features a 1/8 NPT female thread for secure connection to your pressure lines.
Q: What benefits does the photohelic switch/gauge design offer over traditional pressure gauges?
A: The integrated photohelic design combines precise analog pressure indication with the ability to trigger control functions via DPDT snap-action switches. This dual functionality improves operational efficiency, offering both monitoring and automated response within a single durable device.
Q: Where should the 3100MRS Photohelic be installed for best results?
A: For accurate functioning, the unit should be installed indoors in a clean environment, away from excessive moisture or dust. The vertical mounting orientation ensures the gauges diaphragm remains properly aligned for reliable performance.
Q: What maintenance is required to ensure long-term operation of this gauge?
A: Routine inspection of the analog dial, electrical contacts, and connection ports is recommended. Regular cleaning of the polycarbonate window and checking mounting hardware for tightness will help maintain accuracy and longevity. No calibration is needed unless specified by your process requirements.
Q: When is it necessary to adjust the set points for the DPDT snap-action switches?
A: Set points should be adjusted whenever process requirements change, such as shifts in the desired pressure differential for alarms or control equipment. Adjustments can be made easily using the front-panel controls without the need for specialized tools.