Why Ultrapure Water is Becoming Increasingly Important – and How SDI Measuring Devices Help
Whether in semiconductor manufacturing, power plants, or the pharmaceutical industry – clean water is no longer a given, but a highly regulated necessity. While pure water was primarily crucial for laboratory applications in the past, today the demand is growing in industrial processes where impurities can have catastrophic consequences. This is where Silt Density Index – SDI analyzers come into play.
What is SDI (FI) and Why is it So Important?
SDI stands for “Silt Density Index,” also known as Fouling Index – a measure of the amount of particles that could clog a membrane. This is called the fouling index. Especially in reverse osmosis systems, where water is pressed through the finest filters, this value determines the efficiency and lifespan of the systems. A too high index means increased maintenance effort, rising costs, and potential production downtime. High-precision SDI analyzers like the SDI-12 and SDI-22 enable reliable measurement and control of these values.
SDI-12 – Precise Automated Water Quality Measurement
The SDI-12 system measures finest particles in water and determines the Silt Density Index (SDI) for monitoring filters and reverse osmosis systems. They are among the most precise SDI analyzers on the market. And among the few fully automatic systems for measuring the fouling index. The analyzers are used worldwide.
- High Precision – Exact Flow Measurement with State-of-the-Art Sensor Technology
- Fully Automatic – Filter Change, Measurement, and Calculation Occur Independently
- Easy Operation – Touchscreen Control for Quick Settings
- Low Maintenance – Self-Cleaning Mechanisms Extend Lifespan
- Flexibly Applicable – Suitable for Ultrapure and Seawater.
How Does an SDI Analyzer Work?
Such an analyzer measures the fouling rate of a standardized filter membrane. Water is passed through a 0.45 micron filter membrane under constant pressure. The flow rate is measured at the beginning and after a specific time period (e.g., 5, 10, or 15 minutes). The more the flow decreases, the higher the fouling index – and thus the risk of membrane clogging in water treatment. The SDI-12 and SDI-22 are specifically designed for precise and efficient measurements in this area.
Industries Relying on Particle Measurements
Semiconductor Manufacturing
Chip manufacturers require extremely pure water for the production of microchips. Even the smallest particles can destroy the structure of silicon wafers. Measuring devices ensure constant quality of process water and prevent costly failures. Determining the fouling index is also essential for protecting reverse osmosis units (RO)
Power Plants
In power plants, water is used for steam generation. Impurities can not only reduce the efficiency of turbines but also lead to corrosion and deposits in boilers. Regular monitoring with an SDI analyzer helps to optimally control water treatment.
Pharmaceutical Industry
Whether for drug production or equipment cleaning – water must meet the highest purity standards here. Analyzers like the SDI-12 help ensure compliance with these standards and avoid contamination.
Beverage and Food Industry
From beer production to beverage bottling: Water is often the main ingredient. Reliable control ensures that the water remains free of disruptive particles that could affect the taste or shelf life of products.
Desalination Plants
In many regions of the world, seawater desalination is an essential method for obtaining drinking water. Reverse osmosis plants remove salts and other impurities. The particle content is particularly important here, as a high load can quickly clog the membranes. Continuous monitoring helps to reduce operating costs and extend the lifespan of the membranes.
