How to Choose the Right Ultrasonic Level Sensor

Ultrasonic level sensors are widely used in water treatment, chemical processing, storage tanks, and industrial automation due to their non-contact measurement and low maintenance requirements. However, selecting the right ultrasonic level sensor requires more than just checking the price or brand.

This guide explains how to choose an ultrasonic level sensor by analyzing core technical parameters, media characteristics, installation conditions, and brand support—helping you make a reliable and cost-effective decision.

1. Define Your Measurement Requirements

Range, Accuracy, and Response Time

Clearly defining measurement requirements is the foundation of correct sensor selection.

Measurement Range

Key principle: The sensor range must fully cover the actual liquid level variation, with sufficient safety margin.

• Example: If the liquid level varies from 0–8 meters, choose a 10 m ultrasonic level sensor to avoid signal loss near the limit.

• Challenging conditions (agitation, foam, vapor): Select a sensor where the working range is within 50% of the nominal range to improve signal reliability.

Accuracy Requirements

Accuracy should match the control requirements—not all applications need ultra-high precision.

• High-precision applications (chemical reactors, dosing systems):
  Accuracy of ±0.1% is recommended.

• General monitoring (water tanks, reservoirs):
  ±1% accuracy is usually sufficient and more economical.

Response Time

• Fast-changing liquid levels (rapid filling or draining):
  Choose sensors with response time < 0.5 s.

• Stable or static liquid levels:
  1–2 s response time is acceptable.

2. Match the Sensor to the Medium

Material Selection and Anti-Interference Design

Medium Corrosiveness

The probe material directly affects service life.

• Strong acids or alkalis:
  Choose PVDF or titanium probes, such as the SENIX ToughSonic CHEM series.

• Clean water or neutral liquids:
  ABS probes offer sufficient performance at lower cost.

Medium Condition

• Liquids with suspended solids or impurities:
  Select sensors with multi-pulse or echo-processing technology to reduce false readings.

• High-foam environments:
  Install the sensor above the foam layer or choose models with advanced digital filtering.

Temperature Considerations

• High-temperature processes (boilers, hot tanks):
  Sensors should support –40°C to +200°C and include temperature compensation.

• Low-temperature or cold storage applications:
  Choose IP68-rated ultrasonic level sensors to prevent condensation damage.

3. Optimize Environmental Adaptability

Frequency, Beam Angle, and Protection Rating

Operating Frequency

• Short distance, high precision (laboratory vessels):
  High frequency (≥200 kHz) sensors provide narrow beams and accurate readings.

• Long distance or outdoor tanks:
  Low frequency (20–50 kHz) sensors offer stronger penetration and better noise resistance.

Beam Angle Selection

• Calm, flat liquid surfaces:
  Small beam angle (around 8°) improves accuracy.

• Turbulent or fluctuating surfaces:
  Larger beam angle (around 12°) improves measurement stability.

Protection Rating (IP Class)

• Outdoor or humid environments:
  IP65 or higher is recommended.

• Submerged or highly corrosive environments:
  IP68 ultrasonic level sensors ensure long-term reliability.

4. Installation and System Integration

Mounting Methods and Signal Output

Installation Options

• Flange mounting:
  Ideal for large tanks; stable and easy to maintain.

• Threaded mounting:
  Suitable for compact tanks and pipelines.

• Bracket or suspension mounting:
  Common for open channels and reservoirs; ensure the cable is secured to prevent swing.

Signal Output and Communication

• 4–20 mA analog output:
  Compatible with most PLC and DCS systems; excellent noise immunity.

• RS485 / Modbus:
  Ideal for digital control systems and remote monitoring.

• Wireless ultrasonic level sensors:
  Reduce wiring cost in remote or mobile applications.

5. Brand Selection and After-Sales Support

Ensuring Long-Term Measurement Reliability

International Brands

• Siemens:
  High accuracy and long-term stability for oil, gas, and chemical industries.

• Endress+Hauser:
  Excellent performance in wastewater and complex environments.

• VEGA:
  Strong in explosion-proof and high-temperature applications with customization options.

Competitive Domestic Brands

• Aister:
  Flexible customization and high cost-performance ratio.

• East Technology:
  Strong local technical support and fast service response.

• Feejoy:
  Intelligent features and wireless solutions for budget-friendly upgrades.

After-Sales Considerations

• Technical support availability (on-site or remote)

• Long-term spare parts supply

• Calibration and diagnostic services

Reliable after-sales service significantly reduces downtime and lifecycle cost.

Conclusion: Choose Based on Application, Not Just Price

Selecting the right ultrasonic level sensor is a systematic process that balances measurement requirements, medium properties, environmental conditions, installation methods, and long-term support.

By focusing on range, accuracy, material compatibility, frequency selection, and signal integration, you can ensure stable operation, accurate level measurement, and a lower total cost of ownership.

If you need professional advice or product recommendations, feel free to contact us anytime.