The detection principle of online turbidity meter sensors mainly relies on optical detection technology, which uses the scattering, absorption, and transmission characteristics of light to measure the concentration of particulate matter (such as suspended solids, pollutants, etc.) in liquids, and then calculate the turbidity of liquids.
Working principle of online turbidity meter sensor
Light source and detector:
Online turbidity meters typically include a light source (such as LED) and a photodetector. The light source emits a beam of light of a certain wavelength and illuminates the liquid sample.
The core principle of measurement is the scattering and transmission of light. Suspended particles in liquid will scatter or absorb the light emitted, and the scattered light will be captured by the detector of the sensor.
Scattering and absorption:
Scattered light: When a beam of light shines into a liquid, particles suspended in the liquid scatter the beam in different directions. Turbidity meter determines the concentration of particles in a liquid by measuring the scattered light intensity at a certain angle (usually 90 °).
Absorption of light: Particles also absorb some light, reducing the amount of light transmitted. Turbidity meters typically also measure the light intensity passing through liquid samples to further evaluate turbidity.
The relationship between turbidity and light:
According to the Beer Lambert Law, the turbidity of turbid liquids is quantitatively related to the scattering or absorption of light. The changes in scattered and transmitted light are directly related to the concentration of suspended particles in the liquid, so by measuring these changes, the turbidity value of the liquid can be calculated.
Turbidity is usually expressed in units of NTU (Nephelometric Turbidity Unit), with higher NTU values indicating more turbid liquids.
Online measurement and feedback:
Online turbidity meters are commonly used for continuous monitoring of liquid turbidity, such as in industries such as water treatment, wastewater treatment, and chemical engineering, for real-time monitoring of liquid quality.
The sensor converts the measured light scattering signal into an electrical signal, and displays or transmits it to control systems such as PLC (Programmable Logic Controller) or DCS (Distributed Control System) through instruments, providing real-time data for operators to monitor and adjust.
Key Technologies of Online Turbidity Meter Sensor
Angle selection: Sensors usually choose a scattering angle of 90 ° because at this angle, the scattered light signal is strong and can more accurately reflect the concentration of suspended particles.
Light source stability: LED or laser light sources are used to provide stable light output, ensuring measurement accuracy.
Automatic cleaning system: Due to the easy contamination of the sensor surface by sediment, many online turbidity meters are equipped with automatic cleaning systems to ensure that the measuring surface is always kept clean.
Main application areas
Water treatment: used to monitor turbidity in drinking water and sewage treatment, and evaluate whether water quality meets standards.
Industrial production: Monitoring the quality of raw materials, products, or waste liquids in industries such as food, pharmaceuticals, and chemicals.
Environmental monitoring: used to monitor the pollution situation of water bodies and evaluate the ecological environment quality of water bodies.
Common types of turbidity meters
Light scattering type: Evaluating turbidity by measuring the scattering angle of particles towards light.
Light transmission type: Evaluating turbidity by measuring changes in the intensity of light passing through a liquid.
Dual beam type: simultaneous measurement of transmitted and scattered light, with higher accuracy.
Summary:
The online turbidity meter sensor measures the concentration of particulate matter in liquids through optical scattering and absorption principles, providing real-time monitoring of liquid turbidity. It is widely used, especially in water quality monitoring and industrial processes, to ensure that liquid quality meets requirements.