Yokogawa DP Flow Transmitter

The EJA-E series of transmitters is Yokogawa's most recent evolution of the DPharp family of pressure transmitters. Released in 2012, it combines the ruggedness and success of the work-horse EJA-A series with the performance of the thoroughbred EJX-A series to deliver the type of product you have come to expect from Yokogawa.

The EJA115E is a Differential Pressure Transmitter in the series optimized for low flow applications with the addition of an Integral Flow Orifice (IFO) assembly.

The EJA115E is designed to measure accurately, transmit quickly, and do it reliably over time.

  • Accurately: ±0.055% Square Root Output Accuracy
  • Quickly: 90 ms Response Time
  • Reliably: ±0.1% per 10 years Stability (DP)

How the DP Flow Transmitter Works

DPharp digital sensor uses two single crystal silicon resonators vibrating at their natural frequencies. When pressure is applied, one of the resonators goes into tension, while the other goes into compression mode. The CPU directly counts the sensor output frequencies without any additional A/D conversion. Due to the excellent elastic properties of silicon material, the DPharp sensor exhibits greater linearity and repeatability, with no inherent hysteresis. The resonant sensor also provides a large output signal resulting in greater sensitivity and higher turndown.


EJA115E Overview

The low flow transmitter EJA115E is a differential pressure transmitter (Secondary Element) assembled with an integral orifice (Primary Element). The EJA115E is engineered to provide excellent low flow measurement. It outputs an analog 4 to 20 mA DC signal corresponding to the measured flow. Its accurate and stable DPharp pressure sensor can also measure the static pressure. The static pressure can be displayed on the integral indicator or remotely monitored via digital communications. Other key features include quick response, remote set-up using communications, and self-diagnostics. Analog 4 to 20 mA DC with HART (5 or 7) or BRAIN protocol, all digital FOUNDATION Fieldbus or PROFIBUS PA, or 1 to 5 V DC with HART 7 (Low Power) protocols are available. All EJA-E series models in their standard configuration, except the FOUNDATION Fieldbus, PROFIBUS PA and 1 to 5 V DC types, are certified by TÜV as complying with SIL 2 for safety requirement.

DP Flow Transmitters

The EJA115E uses an IFO bore to generate the differential pressure.

IFO Assembly

DP Flow Transmitters

Bore Sizes

Bore sizes avilable are 0.508mm, 0.864mm, 1.511mm, 2.527mm, 4.039mm, or 6.350mm.

One is included with each EJA115E, or an entire set can be purchased separately.

The actual bore used has to be determined based on the process data.

Contact your Yokogawa representative for more information

DP Flow Transmitters


The EJA115E uses the EJA110E differential pressure transmitter as the secondary element.

Digital Performance

Using the latest in semiconductor design and manufacturing technology, Yokogawa designed the DPharp digital sensor to deliver improved performance and reliability over the competitor's old technology analog sensors. Although analog sensors are suitable, the advanced DPharp sensor outperforms even the best analog sensor. A Yokogawa transmitter with the DPharp digital sensor gives the consistent, reliable, accurate measurement needed.

Poor Performance = Lost Money

DP Flow Transmitters

DP Flow Transmitters

Accuracy Under All Operating Conditions

Yokogawa's DPharp sensor can measure the differential pressure (DP), static pressure (SP), and sensor temperature from a single sensor. Given these three pieces of process data, the EJA110E transmitter can compensate the DP measurement for Temperature Effect and Static Pressure Effect in real time. This compensation is referred to as Dynamic Compensation and improves the DP measurement accuracy. Competitor's analog sensors can only measure DP and Sensor temperature. So, theirs can compensate for temperature Effect; but, since the SP measurement is missing, it cannot compensate for Static Pressure Effects.

Poor Performance = Lost Money

Stability Under All Operating Conditions

To some degree, all pressure sensors on the market provide stable measurement with variations in temperature and static pressure. However, what happens when the sensor is over-pressured (pressure > sensor Upper Range Limit (URL)) - like occurs when a manifold is incorrectly sequenced during start-up or shutdown? Alternatively, a process upset? Analog sensors are damaged during these events requiring the transmitter to be recalibrated to return to the accurate operation or even replaced. The EJA110E can withstand overpressure events up to 2,300 psi. Once it returns to normal operating pressure (pressure < URL of the sensor), the transmitter returns to operation within the defined accuracy and stability specifications - no need to recalibrate.  The Yokogawa DPharp sensor has a more significant operational envelope compared to an analog sensor.


DP Flow Transmitters


EJA115E Specifications

The EJA115E measures and transmits a primary and secondary variable. The Primary variable is the differential pressure generated by the IFO. The analog output of this variable can be set to Linear mode (for sending to a flow computer) or Square Root mode (to provide volumetric flow measurement). The Secondary variable is the static line pressure. It can be set to measure off the high-pressure side or the low-pressure side of the IFO as either an absolute or calculated gauge pressure measurement. The secondary variable is transmitted via the digital protocol. A flow computer can use the information.

Measurement Types
Primary Variable Volumetric Flow (Differential Pressure)
Secondary Variable Static Pressure
Reference Accuracy
Primary Variable ±0.055% of DP (Square Root Output)
Secondary Variable ±0.5% of Static Pressure Span
Response Time
Primary Variable 90 ms (M and H Capsule)
150 ms (F Capsule)
Secondary Variable 400 msec
Long Term Stability
Primary Variable ±0.1% of URL per 10 years (DP)
Primary Variable F Capsule: 5:1 (DP)
M Capsule: 50:1 (DP)
H Capsule: 10.5:1 (DP)
Specification Conformance
EJX-A Series ±3σ

EJA115E Capsules

DP Flow Transmitters

DP Flow Transmitters

DP Flow Transmitters

Graphics not to scale



Meter Run

Yokogawa can custom build flanged meter runs of any length and ANSI rating. Meter runs are available with a Yokogawa 3-valve or 5-valve manifold.

Contact your Yokogawa representative for more information.

DP Flow Transmitters

DP Flow Transmitters


The EJA115E low flow transmitter can use the Yokogawa IEC 61518 compliant 3-valve or 5-valve manifold.


Yokogawa manufactures a communicator for your needs. Yokogawa communicators are available for BRAIN Protocol, HART Protocol, FOUNDATION Fieldbus, PROFIBUS PA, ISA100, or MODBUS. All our communicators are compatible with Yokogawa products as well as other products on the market.

DP Flow Transmitters

DP Flow Transmitters


Yokogawa offers a range of loop powered and FOUNDATION Fieldbus remote indicators that can be used to locally monitor data from field instruments installed in difficult to access locations.

Pressure Calibrators

The Yokogawa CA700 Portable Pressure Calibrator uses the same DPharp sensor technology as our EJA-E and EJX-A series pressure transmitters. It provides an accurate and efficient calibration and verification tool for any pressure transmitter or other type of field device.

DP Flow Transmitters

DP Flow Transmitters

Communication Converters

Yokogawa offers communication converters by Moore Industries to convert secondary HART protocol variables to a 4 to 20 mA analog signal or all the HART variables to MODBUS RTU.



  • CENTUM VP Batch package improves productivity.
  • Reduction of operator workload and safe operation.

Download this eBook and learn:

  • The basic physics of pressure
  • Different types of pressure sensors
  • Features of pressure transmitters
  • Pressure transmitters communications standards
  • Key characteristics of pressure
  • Common types of diaphragm seals
Pressure - Low Cut Output Signal With some applications, the output signal can be erratic as the input nears the zero point. One of the most common applications with this issue is differential pressure flow measurement. A differential pressure (DP) ...
Edition 1
Meter Run Yokogawa's EJA115E and EJX115A are low flow volumetric differential pressure flow meters. They employ a simple integrated IFO to generate differential pressure. The unit requires a certain number of upstream and downstream pipe diamete...
Edition 2
688 KB
756 KB
493 KB
1.0 MB
659 KB

Discover the safety features built-in to the Yokogawa digital pressure sensors (DPharp).

813 KB
708 KB
743 KB
717 KB




Is it true that 4-20 mA HART will be phased out in the near future? Is a transducer equal to a transmitter? Tune in to hear the debunking of these myths.

2D/3D Configurator

Looking for more information on our people, technology and solutions?

Contact Us