YOKOGAWA NSPP EJA530A-EAS4N-00DNFU1 EJA530AEAS4N00DNFU1

Yokogawa EJA530A-EAS4N-00DNFU1 | DPharp Gauge Pressure Transmitter — E Capsule 0.5–10 MPa / 4–20mA / BRAIN+HART / IP67

DPharp — Frequency-Based Sensing Without the Analogue Chain

Most pressure transmitters use a capacitive or piezoresistive sensing element that produces an analogue voltage proportional to applied pressure — a signal that requires analogue-to-digital conversion before the transmitter's electronics can process it. Every stage in that chain introduces offset drift, gain drift, noise pickup, and non-linearity.

DPharp removes most of this chain. The monocrystal silicon sensor's resonant frequency changes in direct proportion to applied pressure, and that frequency is counted digitally from the oscillator output without an analogue intermediate step. The measurement is inherently more linear, more stable across temperature variation, and free of the hysteresis that deformable analogue elements show — the sensor returns to exactly the same output at the same pressure whether pressure is rising or falling. The ±0.065% reference accuracy and ±0.1% URL/year long-term stability are direct consequences of this sensor architecture.

Key Specifications

E Capsule — 0.5 to 10 MPa for Medium-to-High Pressure Services

The E-range capsule serves the gauge pressure class above the standard B (2–200 kPa) and C (0.1–2 MPa) ranges — covering oil and gas pipeline monitoring, refinery process lines, steam header pressure, high-pressure chemical reactors, and hydraulic system monitoring. The 25 MPa maximum working pressure provides substantial overpressure tolerance above the 10 MPa measurement ceiling, protecting the capsule against process pressure spikes without damage.

Calibrated span is user-configurable anywhere within the 0.5–10 MPa range at commissioning via BRAIN terminal, HART handheld, or on-instrument push-button. A single instrument covers multiple measurement points through its service life by field reconfiguration, without returning to the factory.

BRAIN and HART — Both Protocols on One Loop

The 4–20mA analogue output carries the measured pressure across the calibrated span. Simultaneously, digital communication is superimposed on the same two-wire loop using either BRAIN protocol (compatible with Yokogawa's BT200 terminal and FieldMate software) or HART (compatible with any HART-capable host system, communicator, or asset management platform).

Through either digital channel: remote zero and span configuration, engineering units and damping settings, process temperature readout from the capsule's built-in temperature measurement, diagnostic status retrieval, and calibration without removing the instrument from service. The digital channel carries continuous self-diagnostic status for predictive maintenance.

The NSPP supply condition means this unit left original project procurement unused — full configuration capability with original factory settings intact.

FAQ

Q1: What does the E capsule code indicate, and what happens below 0.5 MPa?

The E capsule covers calibrated spans of 0.5 MPa minimum to 10 MPa maximum, with a maximum working pressure of 25 MPa. Applications below 0.5 MPa gauge require the D capsule (0.1–2 MPa) variant of the EJA530A. The E capsule is not suited for low-gauge-pressure measurement.

Q2: What is the difference between BRAIN and HART communication?

Both are superimposed digital signals on the same 4–20mA loop carrying identical configuration and diagnostic data. BRAIN is Yokogawa's proprietary protocol, suited to facilities with existing Yokogawa DCS or calibration infrastructure. HART is the open industry standard, compatible with any HART handheld or host system regardless of manufacturer. Both allow full remote configuration without interrupting the analogue loop output.

Q3: Can the calibrated span be changed in the field?

Yes. Zero and span can be reconfigured to any value within the E capsule's 0.5–10 MPa range using a BRAIN terminal, HART handheld, or local push-button. Engineering units, damping, output direction, and display format are all configurable in the field.

Q4: What does ±0.1% URL/year stability mean in practice for calibration intervals?

The transmitter's calibration drift stays within ±0.1% of the upper range limit per year under normal operating conditions. This supports extending calibration intervals beyond the traditional annual cycle — two to four year intervals are defensible in stable process applications where the measurement is not safety-critical. The continuous self-diagnostics flag hardware degradation between scheduled checks.

Q5: What wetted materials are available for corrosive services?

The EAS4N configuration uses SUS316 / SUS316L stainless steel — appropriate for non-corrosive to mildly corrosive services. For higher corrosion resistance requirements (chlorides, oxidising acids, seawater), Hastelloy C-276 wetted parts are available in other EJA530A suffix configurations. Confirm process fluid compatibility with the wetted materials before specifying.