The Yokogawa EJA120E Draft Range Differential Pressure Transmitter is part of Yokogawa's EJA-E Series and is specifically designed for draft range differential pressure measurement. Unlike general-purpose differential pressure transmitters, the EJA120E is optimized for low differential pressure applications where small pressure differences need to be measured reliably. Yokogawa identifies it as the standard traditional-mount model for draft range applications.
The transmitter uses Yokogawa's DPharp single-crystal silicon resonant sensor technology. The sensor provides digital pressure measurement and supports stable process measurement with quick response, remote configuration, and self-diagnostics. The EJA120E can be used for measuring liquid, gas, or steam flow, as well as liquid level, density, and pressure.
The standard EJA120E provides a reference accuracy of ±0.2% of span for its draft-range measurement. For applications requiring improved accuracy, the /HAC option provides ±0.09% accuracy. The transmitter has a 150 ms response time, making it suitable for process applications where relatively fast monitoring of low differential pressure is required.
The standard measurement span is 0.1 to 1 kPa, equivalent to approximately 0.4 to 4 inH₂O, 1 to 10 mbar, or 10 to 100 mmH₂O. The corresponding range limit is -1 to +1 kPa. This dedicated low-pressure range makes the EJA120E particularly suitable for draft pressure measurement and other applications involving small pressure differences.
The EJA120E can output a 4–20 mA DC signal corresponding to the measured differential pressure. Depending on the selected configuration, communication options include BRAIN, HART 5/HART 7, FOUNDATION Fieldbus, PROFIBUS PA, and low-power 1–5 V DC with HART 7. These communication options support remote setup, monitoring, and maintenance in industrial instrumentation systems.
The transmitter also provides self-diagnostic capabilities and supports remote setup through its communication interface. Standard EJA-E configurations, excluding Fieldbus, PROFIBUS, and Low Power types, are certified for SIL 2 safety requirements.
Key Features
- Draft range differential pressure transmitter
- Traditional-mount design
- Yokogawa DPharp single-crystal silicon resonant sensor
- Designed for low differential pressure measurement
- Standard accuracy of ±0.2% of span
- ±0.09% accuracy available with /HAC option
- 150 ms response time
- Measurement span of 0.1–1 kPa
- Equivalent range of 0.4–4 inH₂O
- Range limit of -1 to +1 kPa
- Suitable for liquid, gas, and steam applications
- Flow measurement
- Draft pressure measurement
- Liquid level measurement
- Density measurement
- Process pressure measurement
- 4–20 mA DC output
- BRAIN communication option
- HART 5/HART 7 communication option
- FOUNDATION Fieldbus option
- PROFIBUS PA option
- Low-power 1–5 V DC with HART 7 option
- Remote setup and configuration
- Self-diagnostic functions
- SIL 2 certification for applicable standard configurations
- Multiple process connection options
- Industrial traditional-mount construction
Measurement Range
The EJA120E uses a dedicated E capsule for draft range applications:
- Measurement Span: 0.1–1 kPa
- Equivalent Span: 0.4–4 inH₂O
- Equivalent Span: 1–10 mbar
- Equivalent Span: 10–100 mmH₂O
- Range Limit: -1 to +1 kPa
- Range Limit: -4 to +4 inH₂O
- Range Limit: -10 to +10 mbar
- Range Limit: -100 to +100 mmH₂O
Typical Applications
- Draft pressure measurement
- Air handling systems
- HVAC process monitoring
- Furnace draft measurement
- Boiler draft measurement
- Combustion air monitoring
- Flue gas pressure measurement
- Ventilation system monitoring
- Low differential pressure measurement
- Flow measurement
- Liquid level measurement
- Density measurement
- Gas and air pressure measurement
- Filter differential pressure monitoring
- Industrial process control
