Liquid concentration

• Measurement of the Attenuation of the Transmitted Energy. 

• Frequency Spectrum Analysis by FFT Method (Fast Fourier Transform-Algorythm).

Ultrasonic measurement techniques are widely used for determining the concentration of liquids, as they offer a non-invasive, accurate, and real-time monitoring solution. These techniques are based on the principles of ultrasonic waves propagating through a liquid medium, where the speed of sound and the attenuation of the waves can provide information about the concentration and composition of the liquid.

Principles of Ultrasonic Concentration Measurement

1. Speed of Sound: The speed of sound in a liquid changes with its concentration. By measuring the time it takes for an ultrasonic pulse to travel through the liquid, the concentration can be inferred. The relationship between sound speed and concentration is often calibrated for specific liquids and mixtures.

2. Attenuation: As ultrasonic waves travel through a liquid, they are attenuated (reduced in amplitude) due to absorption and scattering. The degree of attenuation is influenced by the concentration of solutes in the liquid. Higher concentrations generally result in greater attenuation.

3. Frequency: The frequency of the ultrasonic waves can also affect the measurement. Different frequencies can be more or less sensitive to changes in concentration, depending on the liquid and the solutes present.

Components of an Ultrasonic Concentration Measurement System

• Ultrasonic Transducers: These devices generate and receive ultrasonic waves. They are typically piezoelectric materials that convert electrical signals into mechanical vibrations and vice versa.

• Signal Processing Unit: This unit analyzes the received ultrasonic signals to determine the speed of sound and attenuation, and from these parameters, it calculates the concentration of the liquid.

• Display and Control Interface: The processed data is displayed in a user-friendly format, allowing for real-time monitoring and control.

Applications

1. Industrial Process Control: Used in industries such as food and beverage, pharmaceuticals, and chemicals to monitor the concentration of various solutions and mixtures.

2. Environmental Monitoring: Used to detect pollutants or measure the concentration of certain chemicals in water bodies.

3. Biomedical Applications: Used to determine the concentration of biological fluids, such as blood or urine, for diagnostic purposes.

Example Systems

1. Liquisonic® Systems by Sensotech:

   • Features: Real-time measurement, high accuracy, suitable for a wide range of applications.

   • Application: Used in the chemical industry, food and beverage production, and more.

2. Micro Motion Density and Concentration Meters by Emerson:

   • Features: Combines density and ultrasonic measurement for high accuracy.

   • Application: Used in oil and gas, chemical processing, and other industries.

Benefits of Ultrasonic Concentration Measurement

• Non-invasive and Non-destructive: Measurements can be taken without contaminating the sample or altering its properties.

• Real-time Monitoring: Provides immediate feedback, allowing for timely adjustments in processes.

• High Accuracy and Sensitivity: Capable of detecting small changes in concentration, making them suitable for precise applications.