High Accuracy Submersible Liquid Level Sensor with Reliable Long-Term Stability

Level data is only valuable when it is accurate today, next month and next year. The QWY-313 submersible liquid level sensor is built for engineers who need both: high measurement accuracy for precise control, and dependable stability that keeps calibration intervals long and maintenance costs low, in tanks, wells and water pipelines alike.

Why Do You Need a High-Accuracy, Stable Level Sensor?

Inaccurate level measurement quietly costs money: pumps run longer than needed, tanks are overfilled or underfilled, inventory counts are wrong, and process quality varies from batch to batch. Accuracy determines how precisely the control system can hold a level set point, while stability determines how long that accuracy lasts. A sensor that drifts after a few months forces frequent recalibration and slowly corrupts the data history that operators rely on. For water supply, wastewater, chemical dosing and pipeline monitoring, engineers need a sensor that measures precisely from day one and holds its calibration, so that control decisions, inventory records and regulatory reports are all built on trustworthy data.

Working Principle: Stable Hydrostatic Level Sensing

The QWY-313 measures liquid level by sensing the hydrostatic pressure of the liquid column above its 316L stainless steel sensing diaphragm. The pressure is directly proportional to liquid height, and the sensor converts it into a standard 4-20 mA signal that is linear with level. The transmitter electronics are designed for high accuracy and reliable stability, with factory calibration across the full range and a wide power supply tolerance of 12-36 V DC, so the sensor performs consistently even when the plant supply voltage fluctuates. Its rugged stainless steel construction and sealed design ensure that the calibrated accuracy is preserved through years of immersion in demanding environments.

Structural Advantages of the QWY-313

• High accuracy measurement: precise level values for tight process control.
• Reliable long-term stability: holds calibration, minimizing maintenance.
• 316L stainless steel construction: corrosion-resistant for water and chemical service.
• Wide power supply 12-36 V DC: tolerant of fluctuating plant supplies and battery systems.
• Standard 4-20 mA output: direct connection to PLC, DCS and telemetry.
• M20×1.5 electrical connection: rugged, widely used industrial termination.
• Measurement range to 0-1000 psi: covers deep tanks, wells and pipeline pressures.
• Low power consumption below 0.5 W: economical for solar and battery-powered sites.

Pain Point Analysis: 4 Challenging Working Conditions

Application Cases

Product Advantages

• High accuracy for precise level and pressure control
• Reliable long-term stability, low recalibration frequency
• 316L stainless steel wetted construction
• Wide power supply range 12-36 V DC
• Standard 4-20 mA two-wire output
• Range options up to 0-1000 psi
• M20×1.5 rugged electrical connection
• Low power consumption under 0.5 W
• Factory-calibrated, ready to install
• 1-year warranty with manufacturer support

Technical Parameters

SEO FAQ

Q1: How accurate is the QWY-313 submersible level sensor?

The QWY-313 is designed for high accuracy measurement, delivering precise level values that support tight process control and reliable inventory management. The sensor is factory-calibrated over its full range with the 4-20 mA output mapped linearly to the level span, and the calibration is verified at multiple points before shipment. This high accuracy means the control system can hold level set points closely, alarms trigger at the correct values, and inventory records reflect the true tank contents. For applications where even small level errors cause cost or quality problems, the accuracy of the QWY-313 provides the confidence operators need.

Q2: What does reliable stability mean for my application?

Reliable stability means the sensor's calibrated accuracy is preserved over long periods of continuous service, so the reading stays trustworthy without frequent recalibration. Many sensors drift as their sensing elements age and as they are exposed to temperature changes, and this silent drift slowly corrupts the data that operators and control systems depend on. The QWY-313 is engineered with a stable sensing design and rugged construction that minimize drift, keeping measurements consistent month after month. For applications such as groundwater monitoring, inventory accounting and regulatory reporting, this stability is essential because the data must be defensible over time.

Q3: What power supply does the sensor need?

The QWY-313 operates on a nominal 24 V DC supply with a wide tolerance of 12-36 V DC. This wide range is a practical advantage: the sensor continues to measure accurately even when the plant supply voltage sags, when long cable runs cause voltage drop, or when the instrument is powered from a battery or solar-charged system whose voltage varies during the day. The low power consumption of less than 0.5 W means the sensor is economical to power, and multiple sensors can share one supply. For remote monitoring stations powered by solar panels, the wide supply tolerance and low consumption are particularly valuable.

Q4: Can the sensor handle corrosive media?

Yes. The wetted parts of the QWY-313 are made of 316L stainless steel, a low-carbon molybdenum-bearing grade with excellent resistance to corrosion from water, salt water, many chemicals and atmospheric attack. This makes the sensor suitable for potable water, groundwater, wastewater, dilute chemical solutions and other media commonly found in water treatment and industrial applications. For media that are incompatible with 316L, such as concentrated strong acids, please discuss the application with our engineers, who can advise on alternative wetted materials or a chemical seal arrangement to protect the sensor.

Q5: What is the maximum measuring range?

The QWY-313 is available with measuring ranges up to 0-1000 psi, which covers both deep liquid level applications and pipeline pressure monitoring. For level service, the range is selected to match the tank or well depth so that the full 4-20 mA span represents the actual level range, maximizing resolution. For pipeline service, the higher range options measure the water pressure directly. The sensor is factory-calibrated to the exact range ordered, and custom ranges within the maximum can be configured. Tell us your application and we will recommend the range that gives you the best accuracy and resolution.

Q6: How is the sensor installed?

Installation depends on the application. For tanks, the QWY-313 can be mounted through a bottom nozzle using the process connection, or suspended from the top with the cable. For wells, the sensor is lowered to a fixed depth below the lowest expected water level and the cable is anchored at the wellhead. For pipeline monitoring, the sensor mounts on a tee with an isolation valve. In all cases, avoid resting the probe on sludge or debris, protect the cable with strain relief, and route the cable so water cannot run into the electrical connection. The M20×1.5 electrical connection should be terminated with a suitable cable gland to maintain sealing.

Q7: What output signal does the sensor provide?

The QWY-313 provides a standard 4-20 mA two-wire output, the most widely used analog signal in industrial instrumentation. The 4 mA point represents zero level and 20 mA represents full scale, so the signal connects directly to PLC analog inputs, DCS systems, SCADA remote terminal units, panel meters and data loggers without converters. Two-wire loop-powered operation means the same two wires carry both power and signal, simplifying cabling and reducing installation cost. This universal compatibility makes the sensor easy to integrate into both new installations and upgrades of existing level monitoring systems.

Q8: How stable is the sensor over long periods?

The QWY-313 is designed specifically for applications where long-term stability matters, such as unattended monitoring and inventory-critical service. The stable sensing technology and robust 316L construction resist the aging and environmental effects that cause drift in lesser sensors. In practice, users can expect the sensor to hold its calibrated accuracy for extended periods, with recalibration needed only at normal maintenance intervals rather than frequently. For critical applications, we recommend an annual verification against a reference standard, which provides documented confidence in the measurement and satisfies quality and regulatory requirements.

Q9: Can the sensor be used in remote or solar-powered installations?

Yes, the QWY-313 is well suited to remote installations. Its wide 12-36 V DC supply tolerance accepts the variable voltage from solar-charged battery systems, and its low power consumption of under 0.5 W keeps the energy demand small, extending battery life between charges. The rugged 316L construction and sealed design withstand outdoor conditions, and the standard 4-20 mA output connects to the RTUs and data loggers commonly used in remote telemetry. For groundwater monitoring, reservoir supervision and remote pump stations, the sensor provides accurate, stable data with minimal power and maintenance requirements.

Q10: What warranty and support do you provide?

Every QWY-313 is covered by a 1-year warranty against manufacturing defects under normal operating conditions. As the manufacturer, we provide direct technical support including application advice, installation guidance and troubleshooting assistance. We also offer OEM and ODM services such as custom ranges, custom cable lengths, special connections and branding, with a monthly supply capacity of 100 pieces and delivery within 5-8 working days. Calibration certificates and test data can be provided with each order. Contact us with your level range and application details for a quotation and delivery schedule.

Why Choose Our Submersible Liquid Level Sensor?

The QWY-313 is the choice for engineers who measure twice and want to spend once: high accuracy for precise control, reliable stability for low maintenance, 316L construction for long service life, and a wide 12-36 V DC supply tolerance for installation flexibility. As the manufacturer, every sensor is factory-calibrated to your exact range, backed by direct engineering support and delivered within days. When your level data must be accurate and stay accurate, choose the QWY-313.