Technical Tips on Ultrasonic Level Meters

I. Overview of Ultrasonic Level Meters

Ultrasonic level meters (ultrasonic level gauges) are digital level instruments controlled by a microprocessor. During measurement, ultrasonic pulses are emitted by the sensor (transducer), and the sound waves are reflected by the surface of the object and received by the same sensor, where they are converted into electrical signals. The distance from the sensor to the measured object is calculated based on the time between the emission and reception of the sound waves. Since ultrasonic level meters use a non-contact measurement method, the measured medium is almost unrestricted, making them widely applicable for measuring the height of various liquids and solid materials, as well as for distance measurement. In addition to the intelligent LCD display on the local indicator, the DY series ultrasonic level meters (ultrasonic level gauges) also output standard analog signals of 4–20 mA or upper and lower limit alarms (the latest models offer optional RS232 and RS485 digital signal outputs).

II. Working Principle of Ultrasonic Level Meters

Under the control of a microprocessor, the ultrasonic sensor emits and receives ultrasonic waves, and the distance s between the ultrasonic sensor and the measured object is calculated based on the propagation time t of the ultrasonic waves in the air. Since the propagation speed c of sound waves in air is constant, s can be calculated according to the formula: s = ct/2. Furthermore, since the distance H between the ultrasonic sensor and the bottom of the container is constant, the level (liquid level) of the measured object is h = H − s.

III. Technical Features

Extremely low price, high reliability, and high accuracy—fully capable of replacing equivalent imported ultrasonic level meters.
No professional technicians required; ready to use with a single-point setup. The instrument is easy to install on-site, simple to adjust, and requires minimal maintenance.
The ultrasonic level meter (ultrasonic level gauge) features automatic power adjustment, gain control, and temperature compensation, and adopts advanced detection and calculation technologies to improve measurement accuracy. It also has an interference echo suppression function to ensure the authenticity of measurement results.

Adopts SMD technology to improve instrument reliability.

Automatic power adjustment, gain control, and temperature compensation.

Advanced detection technology and rich software functions adaptable to various complex environments.

Equipped with an interference echo suppression function to ensure the authenticity of measurement data.

The sensor is made of PTFE (Teflon) material, making it suitable for various corrosive applications.

Adopts new waveform calculation technology to improve measurement accuracy.

16-bit D/A conversion improves the accuracy and resolution of current output.

Multiple output forms: multi-point switch outputs, high-precision 4–20 mA current output, and RS-232/485 digital communication outputs.

IV. Application Fields
      The ultrasonic level meter (ultrasonic level gauge) is an advanced non-contact level measurement instrument that can completely replace various conventional level meters of other types. It is mainly used to measure liquids such as river water levels, wastewater levels, tank liquid levels, slurry, oil levels, coal piles, and ores, and is widely applied in sewage treatment plants, municipal facilities, power plants, chemical plants, steel mills, pharmaceutical plants, and wineries. The anti-corrosion type ultrasonic level meter is used for measuring various acidic and saline corrosive liquids.