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Yokogawa EJA110E-EMS5A-92NN M1276REE
Model Number: M1276REE (Corresponds to EJA110E-EMS5A-92NN)
Product Introduction:
The M1276REE is a differential pressure / gauge pressure transmitter from Yokogawa’s EJA110E series, utilizing Silicon Resonant Sensor (DPharp) technology. It delivers high-accuracy pressure measurement with HART 7 digital communication and is designed for general industrial process applications.
Detailed content
Function Features:
- Measurement type: Differential Pressure (DP) / Gauge Pressure (GP)
- Silicon Resonant Sensor (DPharp) with no oil fill — direct diaphragm contact with process media
- HART 7 protocol communication (4–20 mA + digital overlay)
- Output signal: 4–20 mA DC (2-wire, loop-powered)
- Built-in LCD display (on head-mounted version) or remote configuration via HART communicator
- Self-diagnostics with alarm notification
- Damping adjustable from 0.1 to 32 seconds
Technical Specifications:
| Parameter | Specification |
|---|---|
| Model Code | EJA110E-EMS5A-92NN (M1276REE) |
| Pressure Range | 0–100 kPa (0–1000 mbar) / 0–400 kPa (selectable) |
| Accuracy | ±0.075% of URL (typical) |
| Overpressure Limit | 1.5 × URL (static), 2.0 × URL (dynamic) |
| Output Signal | 4–20 mA DC (HART 7 superimposed) |
| Supply Voltage | 12–45 V DC (operating), 10.5–42 V DC (with HART) |
| Operating Temperature | -40°C to +85°C (ambient), -40°C to +120°C (process media) |
| Process Connection | 1/2 NPT Female (standard), other options available |
| Wetted Materials | 316L Stainless Steel (diaphragm, body) |
| Protection Rating | IP67 (head-mounted), IP65 (with cover) |
| Explosion Proof | Ex ia IIC T6 Ga (intrinsically safe) |
| Dimensions (W×H×D) | φ80 × 158 mm (approx., with head) |
| Weight | Approximately 1.8 kg (with head-mounted transmitter) |
| Compliance Standards | SIL 2 (IEC 61508), ATEX, IECEx, FM, CSA |
Material Composition:
- Diaphragm: 316L Stainless Steel (electropolished, Ra ≤ 0.4 μm)
- Housing/Body: 316L Stainless Steel
- Process Seal: Fluorocarbon rubber (Viton) or PTFE (optional)
- Electronics Housing: Aluminum alloy with epoxy coating
- Cable Entry: M20 × 1.5 cable gland (stainless steel or brass nickel-plated)
Structure Characteristics:
- Compact head-mounted transmitter design
- Remote seal capillary system available for high-temperature or corrosive applications
- Rotating head (0–360°) for easy display viewing
- Push-button interface for local zero/span adjustment (head-mounted version)
- HART communication terminals accessible via terminal box
Working Principle:
The Silicon Resonant Sensor (DPharp) consists of a silicon diaphragm with two H-shaped resonant beams. When pressure is applied, the diaphragm deflects, causing a change in resonant frequency of the beams. This frequency shift is proportional to the applied pressure and is converted to a digital signal by an on-chip oscillator circuit. The digital signal is then converted to a 4–20 mA analog output and HART 7 digital communication is superimposed on the same current loop. The DPharp technology provides superior long-term stability compared to capacitive or piezoresistive sensors because the resonant frequency is inherently immune to temperature drift and aging effects.
Advantages & Highlights:
- DPharp technology offers ±0.075% accuracy with 0.04% long-term stability per year
- No oil fill eliminates maintenance and environmental concerns
- HART 7 communication enables remote configuration, diagnostics, and range change
- Wide operating temperature range (-40°C to +85°C ambient)
- SIL 2 certified for safety-critical applications
- Intrinsically safe (Ex ia IIC T6 Ga) for hazardous area installations
Applicable Industries:
- Oil & Gas (well testing, separator pressure, tank level)
- Chemical & Petrochemical (reactor pressure, column differential pressure)
- Power Generation (boiler drum level, condenser vacuum)
- Pharmaceutical (cleanroom pressure monitoring)
- Food & Beverage (fermentation tank pressure)
- Pulp & Paper (stock preparation, headbox pressure)
Installation Requirements:
- Install with process connection facing downward for liquid service (to prevent gas trapping)
- Install with process connection facing upward for gas service (to prevent liquid accumulation)
- Use impulse piping with equal length for DP measurement (max 10 m length)
- Fill impulse lines with compatible seal fluid (silicone oil or glycol)
- Torque process connection to 25 N·m (18.4 lbf·ft) maximum
- Ensure cable gland is properly tightened to maintain IP67 rating
Usage Precautions:
- Do not exceed 1.5 × URL static pressure (permanent sensor damage)
- Do not apply pressure to the electronic housing (only to process connection)
- HART communicator must be connected in parallel with the 250 Ω loop resistor
- Do not disconnect the transmitter from the loop while HART communication is active
- Zero calibration should be performed with process isolation valves closed
- Replace diaphragm seal if process media is highly corrosive or abrasive
