Water quality is essential for human health, environmental sustainability, and industrial applications. One of the most critical parameters in assessing water quality is turbidity, which refers to the cloudiness or haziness of a fluid caused by suspended particles. The tool used to measure this parameter is called a turbidimeter, also commonly referred to as a turbidity meter, turbidity monitor, or turbidity analyser.
This article will delve into the practical aspects of turbidity measurement, the functionality of turbidimeters, and the best portable solutions for accurate and reliable field testing, including the PTV 1000 and other recommended Lovibond® portable turbidimeters.
Understanding the Versatility of a Turbidimeter
A turbidimeter is an analytical instrument used to measure a liquid’s turbidity—or relative clarity—. Turbidity is caused by suspended solids such as silt, organic matter, microorganisms, and chemical precipitates, which scatter and absorb light rather than allowing it to pass through cleanly. Turbidimeters help quantify this effect by using optical detection methods to assess how much light is scattered or absorbed by particles in a water sample.
How Does a Turbidimeter Work?A turbidimeter passes a beam of light through a water sample. It measures how much of that light is scattered by suspended particles—the degree of scattering correlates with the concentration of particulates in the water.
Measurement Principles of Turbidity:1. Nephelometric (90-Degree) Measurement• Most modern turbidimeters use nephelometry, where a light source (usually an LED or tungsten lamp) directs light into the sample, and a sensor positioned at a 90-degree angle detects scattered light.• This method is the most widely used and complies with ISO 7027 and EPA 180.1 standards.
2. Ratio and Backscatter Measurements• Advanced turbidimeters may also employ multiple detectors to improve accuracy across different turbidity ranges.
• Ratio turbidimeters use transmitted and scattered light measurements to provide highly accurate readings.
• Backscatter turbidimeters are ideal for measuring high turbidity levels in industrial or environmental applications.
3. Laser and White Light Methods• Some laboratory-grade instruments use laser turbidimetry, which offers enhanced sensitivity for very low turbidity levels.
• Instruments following EPA 180.1 use tungsten-filament lamps, whereas ISO 7027-compliant turbidimeters use near-infrared (NIR) LEDs for consistency in various water conditions.
Units of Measurement for Turbidity
Turbidity is expressed in different units, depending on the standard method used:
• NTU (Nephelometric Turbidity Units) – Standard for most water and environmental monitoring.
• FNU (Formazin Nephelometric Units) – Used for ISO 7027-compliant instruments.
• FAU (Formazin Attenuation Units) – Measures light absorption rather than scattering.
• JTU (Jackson Turbidity Units) – An older method based on visual comparison.
Why Is Turbidity Important in Water Quality Testing?
1. Drinking Water Safety
High turbidity can indicate contamination by pathogens, organic matter, or sediments, interfering with disinfection processes and reducing water quality. Regulatory agencies like the WHO, EPA, and EU set strict turbidity limits for drinking water.
2. Environmental Monitoring
Turbidity affects aquatic ecosystems by reducing light penetration, disrupting photosynthesis in aquatic plants, and impacting fish populations. Turbidimeters are widely used for monitoring rivers, lakes, and oceans.
3. Industrial and Wastewater Treatment
Industries use turbidimeters to ensure compliance with discharge regulations and to optimise filtration processes. High turbidity in wastewater can signal improper treatment or contamination.
4. Food & Beverage, Pharmaceuticals, and Power Plants
Precise turbidity measurement is crucial in breweries, dairy processing, pharmaceutical manufacturing, and cooling water systems to ensure product quality and regulatory compliance.
Which Portable Turbidimeters Are Ideal for Water Quality Testing?
1. TB350 IR – Compact, High-Accuracy Portable Turbidimeter
• Features:• Infrared (IR) LED for stable and accurate turbidity readings.
• ISO 7027-compliant for precise measurements.
• Ideal for both laboratory and field applications.
• Best For:• Drinking water analysis.
• Environmental field testing.
• Industrial water quality monitoring.
2. MD 610 – Multi-Parameter Photometer with Turbidity Function• Features:
• Measures over 120 water quality parameters, including turbidity.
• Bluetooth connectivity for easy data transfer via the AquaLX® app.
• Stores up to 1,000 test results with location and timestamp.
Best For:
• Multi-parameter water quality analysis.
• Municipal and industrial water treatment.
• On-the-go professionals need a versatile testing device.
3. PTV 1000 – Advanced Turbidity Analyser for Continuous Monitoring• Features:• Ultra-precise, real-time turbidity monitoring for process control.
• Laser-based technology for superior accuracy in low-turbidity samples.• Remote data logging and automated calibration capabilities.
Best For:
• Municipal water treatment plants ensuring compliance with drinking water standards.
• Industrial facilities requiring continuous, unattended monitoring.
• Applications where ultra-low turbidity detection is critical.
Choosing the Right Turbidity Measurement Solution
Whether you need a portable turbidimeter for fieldwork or a high-precision turbidity analyser for continuous monitoring, choosing the right instrument depends on your specific application.
Conclusion
Turbidity is a key indicator of water quality, affecting everything from drinking water safety to environmental conservation and industrial compliance. A turbidimeter, whether referred to as a turbidity meter, turbidity monitor, or turbidity analyser, plays a crucial role in ensuring accurate and reliable water quality assessments.
For on-the-go professionals, the TB350 IR and MD 610 offer robust, field-ready solutions. For continuous, automated monitoring, the PTV 1000 provides industry-leading precision.
With PMA’s advanced turbidimeters, you can confidently monitor and maintain water quality—ensuring compliance, safety, and environmental responsibility.
