In industrial scenarios such as chemical, water treatment, and food processing, anti-corrosion ultrasonic level gauges have become the core equipment for level monitoring due to their non-contact measurement, high precision, and strong adaptability. This article is based on ChuchenAC500Taking the series anti-corrosion ultrasonic level gauge as an example, this article systematically analyzes its working principle and daily maintenance points.

1、 Working principle: Precise application of ultrasonic technology

The core principle of anti-corrosion ultrasonic level gauge is based on the emission and reflection characteristics of ultrasonic waves. The liquid level calculation is achieved by measuring the propagation time of sound waves in the air. The specific process is as follows:

1. Ultrasonic emission and reception

The microprocessor controls the ultrasonic sensor to emit high-frequency sound wave pulses (usually20-200kHz）. After the sound wave contacts the liquid surface, it reflects, and the sensor receives the echo signal. The built-in timer records the time difference between the emission and reception of the sound wave（t）.

2. Distance calculation and liquid level conversion

According to the speed of sound wave propagation（cAbout in the air340m/s）Time difference（t）The system uses formulass = c × t / 2Calculate the vertical distance between the sensor and the liquid level（s）. Combined with the total height of the container（H）Obtain real-time liquid level heighth = H - sFor example, if the container is high2mMeasure the distancesfor0.5m, then the liquid levelhfor1.5m.

3. Intelligent compensation and anti-interference design

Temperature compensation: The built-in temperature sensor monitors the ambient temperature in real-time and automatically corrects the sound velocity (which changes with temperature) to ensure-25℃to55℃Stable accuracy within a wide temperature range.

Gain control: dynamically adjust the received signal strength to suppress false echoes from interference sources such as container walls and stirrers.

Interference echo suppression: Filter non target echoes through algorithms to ensure the authenticity and reliability of measurement data.

2、 Daily Maintenance: Key Practice for Extending Equipment Lifespan

1. Regular cleaning and calibration

Sensor cleaning: Wipe the surface of the sensor with a soft cloth every month to avoid the accumulation of dust and scale that may affect sound wave emission. In corrosive media, sensors made of tetrafluoroethylene need to be checked weekly（PTFE）Is the protective layer intact.

Accuracy calibration: Use standard measuring blocks or simulators for zero and range calibration every quarter to ensure that the error is within±0.25%Within.

2. Environmental adaptability inspection

Temperature control: Ensure that the equipment operates at-25℃to55℃Within the range, avoid sensor deformation or circuit failure caused by extreme temperatures.

Protection level maintenance: inspectionIP65Is the protective shell sealed to prevent rainwater and dust from entering and damaging the internal circuit.

3. Output signal and power stability monitoring

Signal output verification: Passed every six monthsRS485/ModbusAgreement or4-20mACurrent loop test output signal stability to ensure compatibility withPLCTheDCSWait for the control system to be compatible.

Power stability check: Use a multimeter to checkAC220V/DC24VFluctuations in power supply voltage should be avoided to prevent equipment restart or data loss caused by unstable voltage.

4. Emergency handling of faults

No echo alarm: Check if the sensor installation angle is vertical (deviation)≤3°）, or whether there is interference such as foam and steam on the surface of the medium.

Data jump: Check for high-frequency device interference in the surrounding area, and if necessary, install a shielding cover or adjust the installation position.

Conclusion

The anti-corrosion ultrasonic level gauge achieves high-precision and maintenance free level monitoring through the combination of ultrasonic technology and intelligent algorithms. By regularly cleaning, monitoring the environment, and calibrating signals, users can significantly extend the lifespan of equipment and reduce the overall lifecycle cost. With the development of industrial Internet of Things, future liquid level gauges will further integrate self diagnosis, remote operation and maintenance functions, providing stronger support for the intelligent transformation of process industries.