Water quality instruments
Submersible Turbidity Sensor Electrode
This product is widely used for online turbidity monitoring in water treatment plants (e.g., inlet, sedimentation tank), wastewater treatment plants, ...
Key Features
Performance Metrics
| Calibration | Standard solution calibration, water sample calibration |
| Operating Temperature | 0~45℃ (non-freezing) |
| Power Supply | 9~36VDC |
| Resolution | 0.01NTU, 0.1NTU, depending on range |
Key Features
Submersible Turbidity Sensor Electrode
The Submersible Turbidity Sensor Electrode is a precision instrument designed to measure the cloudiness or turbidity of a liquid by quantifying the degree of light scattering or absorption caused by suspended particles. This sensor is essential for ensuring water quality and process control across various industries.
How the Turbidity Sensor Works
The operation of a turbidity sensor is based on fundamental optical principles to assess liquid clarity. The two primary methods are the scattering principle and the transmission principle, each suited for different measurement scenarios.
Scattering Principle
This method commonly utilizes infrared light scattering when it encounters suspended particles. A photodetector measures the scattered light intensity at a specific angle, which correlates directly to the turbidity value. For instance, in drinking water testing, this principle detects tiny suspended impurities.
Transmission Principle
Here, a beam of light is passed through the sample. Suspended particles absorb and scatter the light, weakening its intensity. Turbidity is calculated by comparing the incident and transmitted light intensities, a method often applied in wastewater treatment plant monitoring.
Key Components of the Sensor
Light Source
Typically uses LEDs emitting specific wavelengths like infrared light. The chosen wavelength interacts effectively with suspended particles to optimize detection accuracy for the target application.
Detection Chamber
This is where the sample liquid flows, allowing interaction with light. Its design ensures uniform light passage and minimizes interference from factors like internal reflections.
Photodetector
Components like photodiodes receive the scattered or transmitted light and convert it into an electrical signal. Their sensitivity and speed are critical for the sensor's overall performance.
Signal Processing Circuit
This circuit amplifies, filters, and processes the electrical signal, removes noise, and outputs a stable digital or analog signal corresponding to the turbidity value for easy data analysis.
Primary Application Fields for Water Quality Monitoring
The Submersible Turbidity Sensor Electrode is vital for ensuring safety and compliance in water-related processes. Its robust design makes it suitable for continuous, long-term monitoring in diverse environments.
Drinking Water Safety
It monitors the turbidity of both raw and finished water at treatment plants. Real-time data helps control purification processes, ensuring the water supply meets strict hygiene and clarity standards.
Wastewater Treatment Process
By monitoring turbidity at different treatment stages, operators can assess process effectiveness. For example, in activated sludge systems, turbidity changes reflect microbial activity and treatment progress.
Industrial and Environmental Monitoring Uses
Industrial Process Control
In chemical production, controlling reaction liquid turbidity is crucial for product quality. For instance, in paint manufacturing, it affects the final product's uniformity and transparency.
The food and beverage industry relies on turbidity sensors to monitor liquids at various production stages. In beer production, detecting turbidity helps determine fermentation completion and the presence of impurities.
Environmental Water Monitoring
These sensors are deployed in rivers, lakes, and oceans to assess pollution levels and ecological health. Monitoring turbidity is a key indicator in studies of phenomena like lake eutrophication and algal blooms.
Submersible Turbidity Sensor Electrode Features & Specifications
Core Technical Specifications
- Measurement Principle
- 90° scattered light principle, compliant with ISO7027 international standard.
- Accuracy
- Typically ±5% or 0.3NTU (whichever is greater).
- Measurement Range
- Standard: 0.1-1000NTU. Extendable to 0.1-4000NTU for various needs.
- Communication
- RS485 digital interface supporting MODBUS protocol for easy PLC/DTU integration.
- Protection Rating
- IP68, suitable for long-term submersion.
- Max Operating Pressure
- Up to 3 bar.
Advanced Anti-Interference Capability
As a digital smart sensor with MODBUS protocol, it offers strong resistance to signal transmission interference. This design ensures high data accuracy and reliable integration with control systems like PLCs.
Premium Optical Components
The sensor utilizes custom sapphire optical components and specialized filters. This construction makes it highly resistant to ambient light and color interference, guaranteeing stable and reliable measurements under varying conditions.
Self-Cleaning Function for Low Maintenance
An optional automatic cleaning brush is available. Users can set the cleaning frequency to automatically remove bubbles, fouling, and solids from the optical window, significantly extending maintenance intervals and reducing long-term operational costs.
Easy Installation and Deployment
Designed for convenience, this compact turbidity sensor features an NPT3/4 thread for simple submersible installation. It can be directly immersed into tanks, pipelines, or open bodies of water.
The probe cable length is customizable, providing flexibility for different installation scenarios and making it an ideal solution for diverse water quality measurement needs in both industrial and environmental settings.
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Related Questions
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What is RTU Remote Terminal Unit? How does RTU work in water monitoring systems?
View Answer
<p><strong>RTU (Remote Terminal Unit)</strong> is a microprocessor-controlled electronic device that serves as the critical interface between physical field equipment and centralized SCADA (Supervisory Control and Data Acquisition) or telemetry systems. In water monitoring systems, an RTU collects real-time data from field sensors—including flow meters, pressure transmitters, water level gauges, and water quality analyzers—and transmits this information to a central control center via wireless or wired communication networks.</p>
<p><strong>How RTU Works in Water Monitoring Systems:</strong></p>
<ul>
<li><strong>Data Acquisition</strong>: The RTU continuously polls connected sensors through multiple I/O interfaces including analog inputs (4–20mA, 0–10V), digital inputs (pulse, status), and serial communication ports (RS-232/RS-485). For water monitoring, typical sensor inputs include flow rate from electromagnetic or ultrasonic flowmeters, water level from radar or submersible level sensors, pressure from transmitters, and water quality parameters such as pH, turbidity, and dissolved oxygen.</li>
<li><strong>Signal Processing & Logging</strong>: Raw sensor signals are filtered, linearized, and converted to engineering units. The RTU performs local data logging with time-stamped records stored in non-volatile memory, ensuring zero data loss during communication outages. Typical storage capacity supports 10,000+ records with configurable logging intervals from 1 second to 24 hours.</li>
<li><strong>Communication & Telemetry</strong>: RTUs support multiple communication protocols and transport layers. At the field level, <strong>Modbus RTU</strong> (over RS-485) is the most widely adopted protocol for sensor integration, while <strong>Modbus TCP</strong> enables Ethernet-based networking. For long-range telemetry, modern RTUs integrate multi-mode wireless options including <strong>4G LTE, NB-IoT, LoRa/LoRaWAN</strong>, and satellite communication, allowing deployments in remote watersheds, mountain reservoirs, and underground monitoring wells where traditional wired infrastructure is unavailable.</li>
<li><strong>Control & Automation</strong>: Beyond data collection, RTUs execute local control logic—triggering alarms when water levels exceed thresholds, automatically starting or stopping pumps based on tank levels, controlling valve positions for flow regulation, and implementing PID control loops for pressure management in water distribution networks.</li>
<li><strong>Power Management</strong>: For remote sites without grid power, RTUs feature ultra-low-power designs with sleep-mode current consumption as low as 50μA, enabling months of autonomous operation on battery power supplemented by small solar panels (typically 10–50W). Advanced power scheduling wakes the RTU on configurable intervals or upon sensor-triggered events.</li>
</ul>
<p><strong>RTU vs PLC — Key Differences:</strong></p>
<p>While both RTUs and PLCs (Programmable Logic Controllers) perform industrial control functions, they are optimized for different deployment scenarios. RTUs are purpose-built for <strong>geographically distributed, remote, and environmentally harsh installations</strong> with emphasis on wide-area communication, ultra-low power consumption, and extended temperature ranges (-40°C to +70°C). PLCs excel in <strong>centralized factory-floor automation</strong> with high-speed deterministic control, extensive I/O density, and complex sequential logic. In water monitoring, RTUs are the preferred choice for river basin telemetry networks, reservoir monitoring stations, irrigation canal gate control, and urban drainage monitoring—applications where sites may be tens or hundreds of kilometers apart with limited power and no permanent communication infrastructure.</p>
<p><strong>Typical Deployment Architecture:</strong></p>
<p>A typical RTU-based water monitoring system follows a three-tier architecture. At the <strong>field layer</strong>, sensors (flowmeters, level gauges, rain gauges, water quality probes) connect to the RTU via wired interfaces within a monitoring station enclosure. The RTU aggregates and pre-processes data locally. At the <strong>communication layer</strong>, data is transmitted via 4G/NB-IoT/LoRa to a central data server or cloud IoT platform using protocols such as MQTT, HTTP, or the hydrological standard <strong>SL651-2014 / SZY206</strong>. At the <strong>application layer</strong>, SCADA software, water resource management platforms, and mobile dashboards visualize real-time and historical data, generate reports, and issue alarms—enabling water authorities to make informed operational decisions.</p>
<p><strong>Ecolor Technology RTU Solutions:</strong></p>
<p>Ecolor Technology's <strong>Hero V9 Series</strong> offers two primary RTU configurations for water monitoring applications:</p>
<ul>
<li><strong><a href="/EN/products/hero-v9-ec32-measurement-control-terminal">EC32 — Measurement and Control Terminal</a></strong>: A versatile industrial RTU with rich I/O interfaces, Modbus RTU/TCP support, 4G/LoRa/NB-IoT communication, and ultra-low-power design suitable for general water resource monitoring, pump station control, and irrigation automation. Features local data storage, remote firmware upgrade, and wide operating temperature range.</li>
<li><strong><a href="/EN/products/hero-v9-ec60-data-acquisition-terminal">EC60 — Compact Data Acquisition Terminal</a></strong>: A cost-optimized, compact RTU designed for high-density sensor deployments with streamlined I/O, embedded 4G communication, and simplified installation—ideal for large-scale river monitoring networks and smart city drainage monitoring projects where cost per monitoring point is critical.</li>
</ul>
<p>Both models feature solar-ready power input, IP65+ environmental protection, and compatibility with Ecolor's cloud-based water monitoring platform for seamless data integration and visualization.</p>
How many sensors can one RTU handle simultaneously? What types of flow meters and level sensors are supported?
View Answer
<p>The <strong>EC32 RTU series</strong> supports up to 32 analog inputs and 16 digital inputs, while the <strong>EC60 RTU series</strong> can handle up to 60 mixed signal channels for large-scale monitoring stations. Supported sensor types include:</p><ul><li><strong>Electromagnetic flow meters</strong>: LGF series integral/remote types with 4-20mA or pulse signal inputs</li><li><strong>Ultrasonic flow meters</strong>: Clamp-on, inline, insertion, and ultrasonic water meter configurations</li><li><strong>Radar flow meters</strong>: HZ-KSLF multi-band Doppler radar for non-contact measurement</li><li><strong>Level sensors</strong>: Visualized radar level meters, ultrasonic level sensors, submersible pressure transducers</li><li><strong>Water quality sensors</strong>: pH, dissolved oxygen, turbidity, conductivity parameters</li></ul><p>The RTU features <strong>multi-protocol conversion</strong> capabilities, simultaneously handling Modbus, Hart, 4-20mA interfaces. Built-in intelligent algorithms provide data preprocessing, anomaly detection, and edge computing to optimize cloud data transmission efficiency for water treatment and industrial monitoring applications.</p>
What is the empty pipe detection function in electromagnetic flowmeters and how does it work?
View Answer
<p><strong>Empty pipe detection in electromagnetic flowmeters</strong> is a critical diagnostic function that continuously monitors whether the flow sensor's measuring tube is completely filled with conductive liquid. When a pipe runs partially full or completely empty, the electromagnetic flowmeter can produce grossly inaccurate readings—often registering non-zero flow when no actual flow exists, or producing wildly fluctuating values that corrupt flow totalization records and trigger false alarms in downstream control systems.</p>
<p><strong>How Empty Pipe Detection Works:</strong></p>
<p>The detection mechanism relies on the fundamental operating principle of electromagnetic flowmeters. Under normal conditions, when the measuring tube is filled with conductive fluid (typically > 5 μS/cm conductivity), the impedance between the measuring electrodes and the ground/reference electrode remains within a predictable, relatively low range because the conductive fluid provides a stable electrical path. When the pipe becomes empty or partially filled, the fluid path is broken, and the electrode-to-ground impedance increases dramatically—typically by several orders of magnitude—from hundreds of ohms to megaohms or an open circuit.</p>
<ul>
<li><strong>Conductivity-Based Detection</strong>: The most common method. The flowmeter's transmitter continuously injects a small, high-frequency AC excitation signal (typically 50–200 Hz) through the electrodes and measures the resulting impedance. When impedance exceeds a configurable threshold (calibrated for the specific fluid conductivity), an "empty pipe" condition is declared. This method is reliable for most water and wastewater applications where conductivity is moderate to high.</li>
<li><strong>Capacitance-Based Detection</strong>: An alternative method using a separate dedicated empty-pipe electrode or capacitive sensor element embedded in the liner. This method detects changes in dielectric properties when the sensor transitions from liquid-immersed to air-exposed. Capacitance-based detection is especially valuable for <strong>ultra-pure water, deionized water, and low-conductivity fluids</strong> where conductivity-based methods may have insufficient signal-to-noise ratio, as the dielectric contrast between water (εᵣ ≈ 80) and air (εᵣ ≈ 1) remains large regardless of conductivity.</li>
</ul>
<p><strong>Engineering Significance and Benefits:</strong></p>
<ul>
<li><strong>Electrode Protection</strong>: When electrodes are exposed to air in a partially filled pipe while the excitation current continues to flow, electrochemical corrosion accelerates dramatically—particularly for electrodes made of Hastelloy, titanium, or tantalum in aggressive media. Empty pipe detection cuts off excitation to prevent unnecessary electrode degradation, extending sensor service life.</li>
<li><strong>Measurement Accuracy Preservation</strong>: Without empty pipe detection, a partially filled pipe will produce false flow readings because the electromagnetic flowmeter's measurement principle assumes a completely full, axially symmetric flow profile. Any deviation leads to errors that can exceed 50% of actual flow, corrupting billing records, leakage calculations, and process control decisions.</li>
<li><strong>Flow Totalization Integrity</strong>: Empty pipe detection automatically freezes or marks invalid the flow totalizer and pulse output, preventing erroneous volume accumulation from entering billing systems, SCADA databases, or regulatory compliance reports.</li>
<li><strong>Alarm and Interlock Functions</strong>: The detection status outputs to supervisory systems via relay contacts, digital outputs, or fieldbus status bits (HART, Modbus, Profibus), enabling automatic pump shutdown, valve closure, or operator alerts. The 4–20mA analog output can be configured to hold last good value, drop to 0mA/2mA, or drive to 22mA (NAMUR NE43 fault indication) to signal the empty pipe condition unambiguously.</li>
</ul>
<p><strong>Installation Best Practices:</strong></p>
<ul>
<li><strong>Pipe Orientation</strong>: Install electromagnetic flowmeters in vertical pipes with upward flow wherever possible. This ensures the measuring tube remains full even at low flow rates or pump stop conditions. In horizontal installations, position the flowmeter in the lowest section of the pipe run to maintain back-pressure and prevent draining.</li>
<li><strong>Straight Run Requirements</strong>: Maintain minimum upstream (5–10D) and downstream (2–3D) straight pipe lengths to establish a stable, fully developed flow profile. Avoid installing immediately downstream of elbows, tees, valves, or pumps where flow separation and air entrainment are likely.</li>
<li><strong>Electrical Grounding</strong>: Proper grounding is essential for reliable empty pipe detection. Install grounding rings or use electrodes with integrated grounding tips, and ensure low-impedance bonding between the sensor body, process piping, and the transmitter's ground reference to minimize common-mode noise that could cause false empty-pipe triggering.</li>
</ul>
<p><strong>Ecolor Technology Electromagnetic Flowmeter Solutions:</strong></p>
<p>Ecolor Technology offers two configurations of electromagnetic flowmeters with advanced empty pipe detection and diagnostic capabilities:</p>
<ul>
<li><strong><a href="/EN/products/electromagnetic-flow-meter">Split-Type Electromagnetic Flowmeter</a></strong>: Separates the sensor and transmitter for flexible installation in confined spaces or harsh environments. Features adjustable empty pipe detection sensitivity with configurable threshold and response time, multi-language HART/Modbus communication, and ATEX-certified options for hazardous area deployment. Accuracy: ±0.5% of reading.</li>
<li><strong><a href="/EN/products/integrated-electromagnetic-flow-meter">Integrated Electromagnetic Flowmeter</a></strong>: Combines sensor and transmitter in a single compact housing for space-constrained installations and cost-sensitive applications. Offers the same advanced empty pipe detection algorithm with simplified commissioning, local LCD display with diagnostic status indicators, and IP68 submersible options for flooded chamber installations.</li>
</ul>
<p>Both series support empty pipe detection across fluid conductivities from 5 μS/cm to 50,000 μS/cm, ensuring reliable protection in applications ranging from ultrapure water to concentrated brine and slurry measurement.</p>
What are the differences between Doppler radar flowmeter and electromagnetic or ultrasonic flowmeters?
View Answer
<p><strong>Doppler radar flowmeters</strong> offer distinct advantages over traditional flow measurement technologies. Compared to LGF series <strong>electromagnetic flowmeters</strong>, radar flowmeters provide non-contact measurement, eliminating pipeline installation requirements and maintenance issues, especially beneficial for large diameter open channel applications.</p><p>Key differences from <strong>ultrasonic flowmeters</strong> include:</p><ul><li>Measurement method: Radar uses microwave non-contact measurement, while ultrasonic requires contact or proximity to the medium</li><li>Environmental adaptability: Radar is unaffected by water turbidity, ultrasonic is sensitive to particle interference</li><li>Installation convenience: Radar mounts above channels, ultrasonic requires pipe penetration or clamp-on installation</li><li>Measurement range: Radar excels in high-flow open channels, ultrasonic better suited for pipe flow</li><li>Maintenance cost: Radar requires virtually no maintenance, ultrasonic sensors need regular cleaning</li></ul><p>The HZ-KSLF <strong>multi-band radar flowmeter</strong> is ideal for wastewater treatment plants, irrigation channels, and river monitoring, with EC32/EC60 RTU series enabling remote monitoring capabilities.</p>
How do Doppler radar flowmeters achieve accurate measurement and data transmission in river flow monitoring solutions?
View Answer
<p><strong>River flow monitoring</strong> is crucial for water resource management and flood warning systems. The <strong>HZ-KSLF Doppler radar flowmeter</strong> provides advanced technological solutions for comprehensive river monitoring by transmitting microwave signals to measure Doppler frequency shifts from water surface flow, accurately calculating velocity and discharge data.</p><ul><li>Intelligent algorithm optimization: Multi-point velocity measurement technology with automatic compensation for non-uniform flow distribution across river cross-sections</li><li>Environmental adaptability: Unaffected by water turbidity or floating debris, suitable for various river environments</li><li>Complete monitoring solution: Integrated with <strong>visual fusion radar level meters</strong> for simultaneous water level and flow monitoring</li><li>Remote data transmission: Equipped with <strong>EC60 series RTU</strong> supporting 4G/NB-IoT wireless communication</li><li>Solar power system: Ultra-low power consumption design with solar panel power supply for long-term field deployment</li><li>Data management platform: Real-time data upload to monitoring centers with historical data query and alarm functions</li></ul><p>This comprehensive solution has been successfully implemented in multiple watershed river monitoring projects nationwide, providing reliable data support for hydrological departments and environmental agencies.</p>
Can ultrasonic flowmeters accurately measure high sediment content water? What are the requirements?
View Answer
<p><strong>High sediment content water</strong> presents unique challenges for ultrasonic flow measurement, but with proper technology selection and implementation, accurate measurement is achievable. Ecolor Technology offers specialized solutions for high-turbidity applications.</p><ul><li><strong>Sediment Impact Assessment</strong>: Suspended particles scatter ultrasonic signals; measurement becomes challenging when sediment exceeds 25,000ppm</li><li><strong>Frequency Optimization</strong>: Lower frequency transducers (below 0.5MHz) provide better penetration through sediment-laden media</li><li><strong>Signal Enhancement</strong>: Increased transmission power and optimized receiver sensitivity ensure adequate signal strength</li><li><strong>Doppler Technology</strong>: For extremely high sediment content, Doppler-principle ultrasonic meters may be more suitable</li><li><strong>Installation Requirements</strong>: Position after settling tanks in relatively clean sections, avoiding heavy sedimentation zones</li><li><strong>Maintenance Protocols</strong>: Implement frequent cleaning schedules and regular calibration checks</li><li><strong>Alternative Solutions</strong>: Consider electromagnetic or radar flowmeters for excessive sediment conditions</li></ul>