Introduction
Reverse osmosis (RO) process technology is deployed in many industries. This process uses membrane separation which is one of the most economical means to remove suspended solids from feed water. Listed below are examples of some typical RO applications:
- Pretreatment for deionizers for ultra pure water, typically used in the semiconductor industry
- Production of zero-hardness water used for boiler feed water
- Treatment of sanitary waste
- Water purification
The RO function is accomplished by differential pressure across an array of filters. High pressure is applied to the raw water side of the filter that creates sufficient differential pressure across the filter enabling flow of the filtered water to the low-pressure side of the system.
Expected benefits
- Accurate differential pressure measurement is key to filtered water quality.
- Transmitter range flexibility reducing inventory with fewer models required for RO system designs.
- Robust Transmitter design delivering stable output under demanding process conditions.

Challenges
In this semiconductor factory they produce their own deionized water. A cellulose acetate membrane removes dissolved solids from the filtered raw water. Differential pressure values are the key factor determining filter maintenance intervention for cleaning or replacement of filter components.
Application requirements:
- Pressure transmitter must have accurate measurement.
- Pressure transmitter able to withstand plant vibration with more reliable performance than Pressure switches traditionally used.
- Pressure transmitter to deliver long term stability regardless of harsh process conditions of pressure surges and fluctuations that caused zero-point shift and drift with other transmitter brand’s previously used on site.
- Reduce maintenance activities and costs where possible.
Solution
EJA110E medium range unit was chosen to cover the measurement range 0 to 30 kPa (0 to 120 inH2O). The client focused on 0.055 % accuracy of capsule span, superior long-term stability (≤± 0.1 % @ 16 MPa, 2300 psi) and vibration tolerance.
【Static pressure transient test data】
Model: EJA110E M capsule with set range -2 to 2 kPa
Applied static pressure change: 500 kPa in 0.1 Sec
With sudden static pressure changes, the output from EJA110E responds stably and keeps zero every time.
Conclusion
DPharp EJA110E exhibits exceptional stability. Trial results from an EJA110E on this RO process that was evaluated over 6 months presented no zero drift or shift. Maintenance crews were relieved with no maintenance intervention or action required during the evaluation period. The EJA110E consistently delivers accurate and stable measurement of process conditions under real world conditions, resulting in better process efficiency and less maintenance downtime.
Industries
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Water & Wastewater
Water resources are finite, and therefore contributing to a sustainable water cycle is one of the Sustainable Development Goals (SDGs). Yokogawa has been providing advanced digital control solutions for the stable supply of clean and safe water, wastewater treatment for protecting the water environment, water loss management, and optimization of plant operation for reducing CO2 emissions and running costs. Yokogawa works with you to increase your efficiency while ensuring compliance standards …. Smart measuring IA to IA.
Related Products & Solutions
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EJA110E
High-Performance Differential Pressure Transmitter
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EJA115E
- EJA115E Low Flow Transmitter
- DP Transmitter attached to IFO assembly based on EJA-E Series
- Measure accurately
- Transmit quickly
- Reliability over time
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EJA118E
Differential Pressure Transmitter with Remote Diaphragm Seals
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EJA120E
Draft Range Differential Pressure Transmitter
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EJA130E
Differential Pressure Transmitter
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EJA210E
Flange-mounted Differential Pressure Transmitter designed for Liquid-level applications based on the EJA-E series.
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EJA310E
Traditional-mount Absolute Pressure Transmitter based on the EJA-E Series.
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EJA430E
Traditional-mount Gauge Pressure Transmitter
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EJA438E
Gauge Pressure Transmitter with Remote Diaphragm Seal
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EJA440E
Traditional-mount High Gauge Pressure Transmitter
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EJA510E
In-Line Mount Absolute Pressure Transmitter based on the EJA-E Series.
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EJA530E
In-Line Mount Gauge Pressure Transmitter
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EJX110A
High-Performance Differential Pressure Transmitter
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EJX115A
- EJX115A Low Flow Transmitter
- Differential Pressure (DP) Flow Transmitter
- Attached to IFO assembly based on EJX-A Series
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EJX118A
Differential Pressure Transmitter with Remote Diaphragm Seals
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EJX120A
Traditional-Mount Draft Range Pressure Transmitter
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EJX130A
High Static Differential Pressure Transmitter
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EJX210A
Flanged-mounted Differential Pressure Transmitter designed for Liquid-level applications based on the EJX-A Series.
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EJX310A
- EJX310A Traditional-mount Absolute Pressure Transmitter
- ± 0.075% Accuracy
- ± 0.2% per 15 years Stability
- 90 ms Response Time
- Exida and TUV SIL 2/3 Certification
- LPS
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EJX430A
Traditional-mount Gauge Pressure Transmitter
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EJX438A
Gauge Pressure Transmitter with Remote Diaphragm Seal
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EJX440A
Traditional-mount High Gauge Pressure Transmitter
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EJX510A
In-Line Mount Absolute Pressure Transmitter based on the EJX-A Series.
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EJX530A
In-Line Mount Gauge Pressure Transmitter
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EJX610A
High Performance In-Line Mount Absolute Pressure Transmitter based on the EJX-A Series.
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EJX630A
In-Line Mount High Performance Gauge Pressure Transmitter
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EJX910A
This transmitter precisely measures differential pressure, static pressure, and process temperature; then uses these values in a high-perfomance on-board flow computer to deliver fully compensated Mass Flow.
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EJX930A
- EJX930A Multivariable Transmitter
- High static pressure applications
- Differential pressure, Static pressure, process temperature, Mass Flow
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Absolute Pressure
- Absolute Pressure transmitters compare a pressure relative to absolute zero pressure
- Any critical storage and delivery application (i.e., toxic gases)
- Vital to use static reference for accuracy
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Diaphragm Seal System
- Pressure Transmitter Diaphragm Seal System
- Liquid, gas, steam flow
- Liquid level, density, pressure
- High and low temperatures
- Corrosive/high viscosity/toxic
- Clogging, suspended solids
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Differential Pressure Transmitters
- Yokogawa differential pressure transmitters for industrial applications
- Compare two pressures and transmit the difference to a control unit
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Draft Pressure
Draft Pressure instruments are a unique type of differential transmitter that is designed to measure small differences in very low static pressure environments.
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Gauge Pressure
- Gauge pressure instruments
- Compare a pressure relative to atmospheric measure
- Traditional mount and in-line mount transmitters
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Liquid Level
- Liquid Level transmitters for measuring differential pressure to infer level in a vessel
- Yokogawa remote seals with many industrial applications
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Low Flow Integral Orifice
- Low Flow Integral Orifice
- Differential Pressure transmitters infer flow of fluid through a pipe
- Bernoulli's equation- pressure drop across constriction is proportional to square of flow rate
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Multivariable Transmitters (Mass Flow/Multi-sensing)
- Multivariable transmitters
- Simultaneously measure differential pressure, static pressure, external temperature in one device
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Pressure Transmitters
- Yokogawa pressure transmitters and sensors
- Improve industrial operations
- Withstand harsh installation environments
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