Online measurement and control: flow, level, pressure, and water-quality sensors indexed from the Lenntech instrumentation hub.
Process Instrumentation for Water Treatment
Effective water treatment relies on precise monitoring and control. Process instrumentation provides the critical data necessary to optimize operations, ensure water quality, and maintain system efficiency and safety. From source water intake to final effluent discharge, accurate measurements are fundamental for informed decision-making and regulatory compliance.
Key Measurement Parameters
A comprehensive suite of sensors and transmitters is essential for monitoring various physical and chemical properties of water throughout the treatment process.
Physical Parameters
Flow Measurement: Essential for monitoring throughput, dosing control, and mass balance. Technologies include magnetic and ultrasonic flow meters, selected based on fluid properties, pipe size, and accuracy requirements.
Pressure Measurement: Critical for pump control, filter backwash initiation, membrane integrity monitoring, and detecting blockages or leaks within the system.
Temperature Measurement: Influences chemical reaction rates, solubility, disinfection effectiveness, and biological activity. Monitoring temperature is vital for process optimization and energy management.
Level Measurement: Used in tanks, sumps, and clarifiers to prevent overflows, protect pumps from running dry, and manage inventory.
Water Quality Parameters
pH and ORP (Oxidation-Reduction Potential): pH indicates acidity or alkalinity, crucial for coagulation, disinfection, and corrosion control. ORP measures the oxidizing or reducing potential of water, particularly important for disinfection and chemical treatment processes.
Conductivity and Resistivity: Measure the ability of water to conduct electricity, indicating the concentration of dissolved inorganic solids. Conductivity is used for monitoring desalination processes, boiler feedwater quality, and general water purity. Resistivity is used for ultra-pure water applications.
Turbidity: Measures the cloudiness or haziness of water caused by suspended particles. It is a key indicator of filtration effectiveness and overall water clarity, especially important for drinking water quality.
Hardness: Measures the concentration of dissolved minerals, primarily calcium and magnesium. Monitoring hardness is vital for preventing scaling in industrial processes and for softening applications.
Silt Density Index (SDI): A measure of the fouling potential of water, particularly relevant for membrane filtration systems (RO, UF, NF) to predict membrane performance and cleaning cycles.
Dissolved Oxygen (DO): Crucial for biological treatment processes, aeration control, and corrosion monitoring.
Specific Ion Analysis: Portable instruments can measure specific ions such as iron, manganese, sulfates, and nitrates, providing insights into raw water quality and treatment effectiveness.
Chemical Oxygen Demand (COD): A measure of the amount of oxygen required to oxidize organic matter in water, used for assessing organic pollution load, particularly in wastewater.
Disinfection Residual Measurement
Maintaining appropriate disinfection levels is paramount for public health.
Ozone Measurement: Continuous monitoring of dissolved ozone is critical for effective disinfection while preventing over-dosing. Instruments can offer ranges such as 0.00 – 5.00 mg/L or 0 – 2 ppm, with typical accuracies within 10-20% when operated near room temperature. Calibration checkers utilizing UV lamp sources can provide known output concentrations for verification.
Chlorine Dioxide Measurement: Similar to ozone, monitoring chlorine dioxide residual ensures adequate disinfection while managing potential by-products.
System Integration and Control
Modern water treatment plants rely on integrated control systems to manage complex processes. Instrumentation plays a vital role by providing real-time data to these systems.
Instrument Controllers: Dedicated controllers integrate data from multiple sensors, enabling automated process adjustments, alarm management, and remote monitoring.
Outputs and Communication: Sensors and transmitters typically provide industry-standard outputs such as 4-20 mA or 0-2 VDC for connection to Programmable Logic Controllers (PLCs) or other control systems. Digital communication options like USB and RS-232 are also common for data logging and direct computer interface.
Data Logging: Software solutions facilitate real-time measurement logging with date and time stamps, compatible with common operating systems. Communication cable sets, including USB to serial adapters, enable data transfer.
Alarm Devices: Remote alarm panels with visual (strobe lights, multi-color indicators) and audible (pulsed alarms at 85 dB) alerts provide immediate notification of process deviations. These devices often feature adjustable alarm set-points and can provide 4-20 mA or relay outputs to control systems.
Instrumentation Selection and Maintenance Considerations
Selecting the right instrumentation is crucial for reliable operation and long-term performance.
Measurement Point Selection: The location of a sensor significantly impacts the representativeness and accuracy of the measurement. Careful consideration of flow dynamics, mixing, and potential interferences is essential.
Materials of Construction: The wetted materials of sensors and probes must be compatible with the fluid chemistry (pH, temperature, chemical concentrations) to prevent corrosion, degradation, and measurement drift.
Calibration and Maintenance: Regular calibration against certified standards is necessary to ensure sustained accuracy. Maintenance, including cleaning and sensor replacement, should follow manufacturer guidelines to maximize sensor lifespan and reliability.
Certified Data: Specific performance characteristics, including measurement ranges, accuracies, operating conditions, and interference data, are detailed in the OEM datasheets for each instrument. These specifications are critical for proper application and system design.
Indexed coverage:China-based brands 0 · International brands 15 · Total 15
China-based brands
No China-based brand profile is available in this category yet.
International brands
International brands: 15
Each brand card links to a brand profile with model profiles and datasheet entries.
BMT Ozone Measurement
International
Brand profile
BMT Messtechnik is a German ozone-measurement specialist with analyzers, monitors, ozone sources, and calibration accessories for gas and dissolved ozone work. Its influence is in ozone projects where accurate concentration measurement, sample conditioning, pressure/temperature compensation, and reliable monitoring determine safe operation. BMT Ozone Measurement's position in instrumentation and sensors is defined by product families such as Ozone analyzers 964. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Ozone Analyzer BMT 964, Ozone Analyzer BMT 964 BT and Ozone Analyzer BMT 964 C. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Endress+Hauser is a family-owned process instrumentation and automation group founded in 1953. Its influence in water and wastewater plants comes from a broad measurement portfolio - flow, level, pressure, temperature, and liquid analysis - plus calibration, diagnostics, and control-system integration for continuous process reliability. Endress + Hauser Flow measurement's position in instrumentation and sensors is defined by product families such as Coriolis flowmeters, Electromagnetic flowmeters, Ultrasonic flowmeters and Thermal mass flowmeters. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Proline Cubemass C 300, Proline Cubemass C 500 and Proline Promass A 100. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Endress+Hauser is a family-owned process instrumentation and automation group founded in 1953. Its influence in water and wastewater plants comes from a broad measurement portfolio - flow, level, pressure, temperature, and liquid analysis - plus calibration, diagnostics, and control-system integration for continuous process reliability. Endress + Hauser Level measurement's position in instrumentation and sensors is defined by product families such as Vibronic point level, Radar level, Ultrasonic level and Microwave barrier level. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Liquiphant Failsafe FTL80, Liquiphant FTL41 and Liquiphant FTL43. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Endress+Hauser is a family-owned process instrumentation and automation group founded in 1953. Its influence in water and wastewater plants comes from a broad measurement portfolio - flow, level, pressure, temperature, and liquid analysis - plus calibration, diagnostics, and control-system integration for continuous process reliability. Endress + Hauser Liquid analysis's position in instrumentation and sensors is defined by product families such as pH sensors &Transmitters, Assemblies, Conductivty sensors & transmitters and Oxygen sensors & transmitters. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Ceraliquid CPS41, Ceramax CPS341D and CPS31D. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Endress+Hauser is a family-owned process instrumentation and automation group founded in 1953. Its influence in water and wastewater plants comes from a broad measurement portfolio - flow, level, pressure, temperature, and liquid analysis - plus calibration, diagnostics, and control-system integration for continuous process reliability. Endress + Hauser Pressure measurement's position in instrumentation and sensors is defined by product families such as Absolute and gauge pressure measurement and Differential pressure measurement. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Cerabar PMC11, Cerabar M PMC51 and Cerabar M PMC51B. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Endress+Hauser is a family-owned process instrumentation and automation group founded in 1953. Its influence in water and wastewater plants comes from a broad measurement portfolio - flow, level, pressure, temperature, and liquid analysis - plus calibration, diagnostics, and control-system integration for continuous process reliability. Endress + Hauser temperature measurement's position in instrumentation and sensors is defined by product families such as Industrial thermometers, Thermowells, Modular thermometers and Temperature transmitters. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include RTD T13, T14, T15, RTD T53, T54, T55 and RTD TH11, TH12. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
EWS International is a water-treatment controller specialist whose public site positions the company in microprocessor-based controllers for industrial water treatment. In this catalog it is relevant where softening, filtration, dosing, conductivity, or plant control logic requires dedicated controllers rather than only standalone sensors. EWS's position in instrumentation and sensors is defined by product families such as Controllers for Reverse Osmosis, Controllers for Ultrafiltration, Controllers for Filters and softeners and Controller for Demineralisation. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include OS3015, OS3020 and OS3030. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Hach is a water analysis brand with water-quality analysis roots going back to 1933. Its product influence is strongest in water and wastewater operations that need laboratory methods, online analyzers, field instruments, reagents, and data tools to make treatment decisions faster and more repeatable. Hach Instrumentation's position in instrumentation and sensors is defined by product families such as flow, level, pressure, temperature, analytical sensors, analyzers, transmitters, and monitoring assemblies. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include BOD Direct Plus, DR 6000 Spectrophotometer series and LT200 Thermostat. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
METTLER TOLEDO is a global precision-instrument company serving laboratory, industrial, product-inspection, and process applications. In water treatment it is relevant for analytical measurements such as pH, ORP, conductivity, dissolved oxygen, and process monitoring where accuracy, calibration discipline, and digital integration affect compliance and uptime. Mettler Toledo instrumentation's position in instrumentation and sensors is defined by product families such as flow, level, pressure, temperature, analytical sensors, analyzers, transmitters, and monitoring assemblies. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include M200 1-2 Channel Multiparameter Transmitter, M300 ISM 1-2 Channel Multiparameter Transmitter and M400 ISM Type 1-2 Channel Transmitter. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
ProMinent is a German dosing and water-treatment technology company whose history begins in 1960 with Chemie & Filter GmbH in Heidelberg. The brand is influential in chemical metering, disinfection, sensors, controllers, and packaged dosing systems where accurate dosage, safety interlocks, and online measurement determine treatment stability. Prominent Sensors's position in instrumentation and sensors is defined by product families such as Reliable sensors. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include DULCOTEST LF/LFT/LFTK, DULCOTEST PHEI 112 pH and DULCOTEST RHES Pt SE. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
SYCON analyzers are online water-analysis instruments from RLS Wacon analytics for continuous monitoring of water-treatment parameters. The family is most relevant to hardness monitoring, softening protection, boiler and cooling water, and RO pretreatment where limit-value control and repeatable reagent-based analysis are needed. Sycon analyzers's position in instrumentation and sensors is defined by product families such as Sycon 2602 BASIC online analyzer, Sycon 2702 BUDGET online analyzer and Sycon 2802 PREMIUM online analyzer. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Flyer, SYCON 2602 en L and SYCON 2702 en L. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Testomat is the online analyzer family from Gebrüder Heyl / Heyl Analysis Technologies, best known for automatic hardness and water-quality monitoring in treatment facilities. It is important where softeners, RO pretreatment, cooling circuits, boilers, and drinking-water installations need continuous residual-hardness or limit-value supervision. Testomat's position in instrumentation and sensors is defined by product families such as Automatic hardness control, The Testomat Family › Testomat 2000, The Testomat Family › Testomat 2000 DUO and The Testomat Family › Testomat 2000 CAL. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Testomat EVO TH, Testomat 2000 and Testomat 2000 DUO. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Testomat is the online analyzer family from Gebrüder Heyl / Heyl Analysis Technologies, best known for automatic hardness and water-quality monitoring in treatment facilities. It is important where softeners, RO pretreatment, cooling circuits, boilers, and drinking-water installations need continuous residual-hardness or limit-value supervision. Testomat: hardness controller's position in instrumentation and sensors is defined by product families such as Automatic hardness control, The Testomat Family › Testomat 2000, The Testomat Family › Testomat 2000 DUO and The Testomat Family › Testomat 2000 CAL. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include Testomat EVO TH, Testomat 2000 and Testomat 2000 DUO. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
AQL is represented here as an ozone-measurement instrument family rather than a broad corporate platform. The series is useful where engineers need compact handheld or fixed ozone monitors for air or process checks, with selection driven by measured medium, range, output functions, alarms, and maintenance practice. The AQL Ozone family's position in instrumentation and sensors is defined by product families such as Options:. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include S100, S200 and S300. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
Wallace & Tiernan is a Xylem disinfection brand with more than a century of association with gas chlorination, disinfection, chemical dosing, analyzers, controllers, and chlorine dioxide systems. In water plants it is relevant where residual control, chemical feed, safety, and analyzer/controller integration are part of a disinfection train. Wallace & Tiernan Analyzers - Controllers's position in instrumentation and sensors is defined by product families such as flow, level, pressure, temperature, analytical sensors, analyzers, transmitters, and monitoring assemblies. The portfolio is best understood inside online water-quality measurement, process control, chemical dosing feedback, plant monitoring, and safety interlocks, where engineers compare the technology route, family boundaries, and duty fit before narrowing to individual models. Representative series on this page include OPC Server, Process Monitor System and Acutec 35 Gas Detection System. Engineers should compare measured parameter, range and accuracy, wetted materials, calibration workflow, and control-system communication. These cues help users understand the brand's strongest fit before moving into the model index and product cards for finer comparison.
