PROCESS ANALYTICS

Reverse Osmosis Systems

Reverse osmosis (RO) systems are used for water treatment in many industrial applications. In reverse osmosis, dissolved salts are filtered out of the water, and contaminants and even nanoparticles (bacteria and viruses) are removed. This process is used for the treatment of ultra-pure water for power plants and drug production, as well as in drinking water treatment and water desalination.

Energy

Key Facts About the Application

Sector

Reverse osmosis systems

Application

3 applications (1. pH loop for verifying permeate quality, 2. Conductivity loop for verifying module leakage, 3. ORP loop for verifying concentrated water)

Measured Parameters

pH, conductivity, and ORP

Main Requirements

Inline measurement of pH value, ORP, and conductivity

Measurements in Ultra-Pure Water and Concentrated Water

Description of application

In power plants, the reverse osmosis system is used to produce boiler feed water for steam generation. The diagram shows a typical boiler feed water system with RO technology. pH value, redox potential, and conductivity must be monitored after every RO step and in every RO segment in the main collection pipe.

Requirement of the application

Reverse osmosis monitoring systems require the inline measurement of pH value, redox potential, and conductivity. Adding various chemicals during the process prevents organic or inorganic deposits from adhering to the osmosis membrane. If metering is not precise, the membrane can be damaged and favorable conditions for biological growth may be established. Consequence: The systems must be shut down and cleaned in a complex process. The option to measure conductivity values in the micron range and the setpoint deviation of redox potential and pH value is one of the main prerequisites for extending the service life of the membrane and saving the costs of early replacement. The quantity of chemicals used, including chlorine and sodium bisulfite, can be significantly reduced when conductivity, pH value, and redox potential are precisely measured.

Why Knick?
The SE604 conductivity sensor from Knick is the only sensor with removable outer electrodes for easy cleaning and handling. The recommended pH sensor, SE558, has an electrolyte reservoir for accurate, stable measurement in probes with low conductivity. The greatest flexibility possible with Knick transducers (e.g., Stratos Multi): one system for all measuring loops with flexible configuration.

Associated Products

SE558 pH Sensor | Memosens | 120 mm | Ex | For ultrapure water, water and analytical chemistry

Product number:

SE558X/1-NMSN

SE604 2-Electrode Conductivity Sensor | 7-Pole | Measuring range from 1 nS/cm to 1000 μS/cm

Product number:

SE604

SE565 ORP Sensor | Memosens | 120 mm | Ex | For hygienic processes and sterile applications

Product number:

SE565X/1-NMSN

ARF201 Flow-Through Fitting | PP-H | One sensor

Product number:

ARF201

ARF200 Flow-Through Fitting | Stainless steel or Hastelloy C22 | One sensor | Process connection via cutting ring coupling

Product number:

ARF200

Stratos Multi E461N Multiparameter Transmitter | Memosens/Analog Sensors | 1-Channel |PROFINET | 2x 4…20 mA Outputs

Product number:

E461N

Associated Industries and Applications

Energy

In power plants, water is used in many processes with completely different requirements: for example, for steam generation, cooling, and flue gas scrubbing.

Ion Exchanger Systems

Measurement of pH values, dissolved oxygen, and conductivity in boiler feed water, steam, and condensate in combined gas turbines in power plants.

Boiler Feed Water Circuits

Measurement of pH values, dissolved oxygen, and conductivity as key parameters in the boiler feed water circuit.

Cooling Water Systems

Measurement of pH value, redox potential, and conductivity in cooling water, which has to be continuously treated with acid and biocides.

Monitoring Steam Generators

Since steam generators fulfill application-critical functions and the cost of their downtime or replacement is extremely high, damage caused by wear should be prevented by monitoring water quality.

Flue Gas Desulfurization

pH value measurement in the pre-scrubber, the neutralization phase, and the lime scrubber as part of the flue gas desulfurization process in power plants.

Water Treatment Systems

Measurement of pH value, dissolved oxygen, and redox potential in various applications during the water treatment process of power plant wastewater.

Combined Cycle Power Plants

Measurement of pH values, dissolved oxygen, and conductivity in boiler feed water, steam, and condensate in combined gas turbines in power plants.

Energy Industry Brochure

Overview of specific applications and product solutions in different areas of power plants.

Latest Blog Post

SE605H conductivity sensor with CondCheck: Integrated sockets for connecting a resistance decade

Mar 2025

Process Analytics

Pharma, Sensor, Conductivity

SE605H Conductivity Sensor with CondCheck

The SE605H conductivity sensor with CondCheck enables USP 645 verification without interrupting the measuring chain.

Knick’s large, international team at its ACHEMA 2024 trade fair booth.

Jul 2024

Process Analytics

Achema

ACHEMA 2024 - Review and Impressions

A brief cinematic retrospective of our trade fair booth, Knick’s international team, and a successful booth party.

Feb 2024

Process Analytics

Uniclean700, Launch

Uniclean 700 Series - Modular control system for automated sensor cleaning

With the Uniclean 700 series, Knick is introducing a modular control system, that can be installed very quickly and cost-effectively as a flexible entry-level solution for automated sensor cleaning.

Dec 2023

Company

|

Interface Technology

|

Process Analytics

Knick Austria - direct customer contact in Austria from 2024

Reorganization of sales in Austria and new contacts in the field of process analytics and interface technology

Apr 2023

Process Analytics

Launch, Fitting, WA111

Robust WA111 Retractable Fitting Made of Plastic for Highly Corrosive Operating Conditions

The plastic WA111 retractable fitting is a robust and cost-effective solution for corrosive processes and environments. It is equipped with a secure lock function and multiple nozzles for thorough sensor cleaning.

Apr 2023

Process Analytics

Launch, Fitting, WA155

Successful joint project : Knick developed the special Ceramat WA 155 retractable fitting for optical probes from SOPAT

In cooperation with SOPAT, Knick developed a special Ceramat fitting for optical probes for automatic cleaning in fouling processes.

Apr 2023

Process Analytics

Conductivity, Phamacy, pH

pH and conductivity measurement in vaccine production

Pharmaceutical contract manufacturer relies on Knick's transmitters for modular production plants for Covid-19 vaccines.

Apr 2023

Process Analytics

Sensor, Conductivity, SE625

Sturdy 2-Electrodes Conductivity Sensor SE625 with Coaxial Electrodes made of Titanium

The SE625 ensures reliable and accurate determination of the conductivity of ultrapure water in the semiconductor industry.

Jan 2023

Process Analytics

ARD75

Sensor Adapter with Lock Function Enables Safe and Thorough Cleaning

Sensor adapter with locking gate for safety and thorough cleaning of sensors in the immersion fitting ARD75 without the need

Nov 2022

Process Analytics

Protos II 4400, Module

Up to six Sensors on one Transmitter Protos II 4400 via Modul MSU4400-180

Users can now connect up to six Memosens sensors simultaneously.

Aug 2022

Process Analytics

Achema, Exhibition

ACHEMA 2022 - Knick at the world forum for the process industry

In August 2022, the international process industry met at the ACHEMA. Knick presented the cCare system and industrial applications in a new concept.

Jun 2022

Process Analytics

Sensor, pH, SE555, ORP

Combined pH- and ORP-Sensor SE555X/*-AMSN

Combined pH and ORP measurement in one sensor SE555 saves place and equipment costs for demanding requirements in the chemical industry, the food sector and for hygienic applications.

Apr 2022

Process Analytics

MemoTrans

Ultra Compact Transmitter for Memosens Sensors

The new ultra compact MemoTrans MT201 transmitter plugs directly onto the Memosens sensor in the fitting and communicates via 4-20 mA HART protocol.

Feb 2022

Process Analytics

Protos II 4400, Stratos Multi, Software, ProgaLog

Conveniently configure transmitters offline on a PC - ProgaLog 4000

Conveniently configure all flexibly configurable Stratos Multi and Protos II 4400 transmitters offline, save settings, duplicate for further transmitters, and create documentation for audits.

Feb 2022

Process Analytics

Stratos Multi, Transmitter

New Stratos Multi E461N transmitter with Profinet

The interface enables continuous communication of process variables and predictive maintenance from the field level to all common process control systems.

Jan 2022

Process Analytics

Memosens

Memosens 2.0: Evolution of digital data transfer

As one of the two initiators of Memosens, Knick is constantly developing the technology.

Nov 2021

Process Analytics

Sensor, Conductivity, Ex, SE656, SE655

SE655X Digital and SE656X Digital - Digital Conductivity Sensors with Ex Certification

The SE655X digital and SE656X digital conductivity sensors with Memosens protocol are now also available with Ex certification.

Nov 2021

Process Analytics

Exhibition, Switzerland, Ilmac

ILMAC 2021 in Basel - Trade Show Review by Knick Schweiz AG

Knick Schweiz AG exhibited at ILMAC in Basel and gives a brief review of what it's like to have finally met customers at the show again.

Oct 2021

Process Analytics

Stratos Multi, Transmitter, Ex

Stratos Multi E401X- Multiparameter Transmitter for Hazardous Locations

The new Multiparameter Transmitter Stratos Multi E401X can now also be used in hazardous locations, installed in Ex Zone 2.

May 2021

Process Analytics

Transmitters, Stratos Multi

Stratos Multi E471 with EtherNet/IP for process optimization

EtherNet/IP communication protocol allows the transmitter to be easily integrated into Industrial Ethernet networks as PCS.

May 2021

Process Analytics

Sensor, Conductivity, Launch, SE656

New SE656N digital conductivity sensor

New toroidal Digital Conductivity Sensor with a large measuring range and consisting of PFA for using in aggressive media

Mar 2021

Process Analytics

Protos II 4400, Profinet

Transmitter for the process industry with PROFINET module

The PROFINET industrial Ethernet standard is becoming an increasingly important aspect of process engineering in the “Industry 4.0” environment.

Jul 2020

Process Analytics

Launch, Fitting, ARD170

High-quality immersion fitting for mobile applications

ARD 170 enables measurements even in deep water

Jul 2020

Process Analytics

Fitting, ARD50, ARD75

Modular immersion fitting as an electrically conductive variant

Knick is expanding its portfolio of fittings for liquid analysis with additional electrically conductive (EL) variants.

Apr 2020

Process Analytics

Launch, Transmitters, Stratos Multi

New multiparameter transmitter Stratos Multi

Knick is launching the the next generation in its Stratos analyzer product line.

Feb 2018

Process Analytics

Sensor, Fitting

How to get the sensor into the process

Sensors as the direct interface to the process must be exactly matched to the chemistry of the measured medium and to the prevailing pressure and temperature conditions.

Apr 2017

Process Analytics

MemoRail Modbus

Powerful compact analyzer boosts performance while reducing costs

It has long been common practice when taking pH/ORP, conductivity, and oxygen measurements that a fixed analyzer be mounted near the sensor. The analyzer serves several purposes.