Pressure reducing regulator equipped with Yokogawa VY series vortex flowmeter and EJX120A ventilation range differential pressure transmitter

The Yokogawa EJX120A represents a pinnacle of engineering in the field of industrial pressure measurement. As a flagship model within Yokogawa's renowned EJA-E Series, the EJX120A is a high-performance, microprocessor-based differential pressure transmitter designed to deliver exceptional accuracy, unwavering reliability, and long-term stability in the most challenging process environments. It is the instrument of choice for critical applications across industries such as oil and gas, petrochemical, power generation, and chemical processing, where precise pressure measurement is paramount for safety, efficiency, and product quality.

At the heart of the EJX120A lies Yokogawa's proprietary Silicon Resonant Sensor technology. This cutting-edge sensor is a significant advancement over traditional strain-gauge or capacitive sensors. The sensor consists of a single-crystal silicon wafer where two H-shaped resonators are excited at their natural frequency. When differential pressure is applied to the sensor, it causes a stress change, which in turn alters the resonant frequency of the resonators. The microprocessor detects this frequency difference and converts it into a highly stable, precise 4 to 20 mA DC output signal or a digital signal via protocols like HART®, FOUNDATION™ Fieldbus, or BRAIN.

This resonant technology is the source of the EJX120A's renowned advantages:

• Unmatched Accuracy: It achieves a remarkable accuracy of up to ±0.04% of calibrated span, ensuring that even the smallest changes in process pressure are detected and communicated.

• Excellent Stability: Long-term drift is minimized to ±0.25% of URL per 10 years, drastically reducing the need for frequent recalibration and maintenance, which lowers the total cost of ownership.

• High Noise Immunity: The frequency-based detection method is inherently resistant to vibration, temperature fluctuations, and static pressure variations, ensuring a reliable signal in electrically noisy industrial settings.

The EJX120A is built to last. Its rugged construction includes a hardened stainless steel flange and a robust aluminum or stainless steel housing, providing superior protection against corrosion and mechanical impact. The transmitter complies with stringent international safety and quality standards, including SIL 2/3 (Safety Integrity Level) certification for use in safety instrumented systems (SIS).

Key operational features include:

• Wide Rangeability: It offers an extensive turndown ratio (up to 200:1), allowing a single transmitter to cover a broad range of pressures, which simplifies inventory management.

• Advanced Diagnostics: Built-in self-diagnostics continuously monitor the health of the transmitter, detecting issues like impulse line blockage, sensor failure, or electronic faults, enabling predictive maintenance.

• User-Friendly Interface: Local configuration is made simple through the integral magnetic switch or a HART communicator, allowing for easy zero adjustment, range setting, and parameter configuration without opening the electronics compartment, thus maintaining the unit's weatherproof and explosion-proof integrity.

• Flexible Communication: Support for the major digital fieldbus protocols ensures seamless integration into both new and existing plant control systems.

The EJX120A is exceptionally versatile and is ideally suited for:

• Flow Measurement: Accurately measuring flow by detecting the differential pressure across primary elements like orifice plates, venturi tubes, and flow nozzles.

• Level Measurement: Precisely monitoring the level of liquids in tanks and vessels under a wide range of pressures and temperatures.

• Pressure Measurement: Gauging absolute and gauge pressure in pipes and equipment.

In summary, the Yokogawa EJX120A Differential Pressure Transmitter is more than just a measurement device; it is a critical component for modern industrial automation. Its blend of supreme accuracy, legendary reliability, and intelligent features makes it an indispensable tool for engineers seeking to optimize their processes, enhance plant safety, and achieve superior operational excellence.