UV Multi-parameter Meter Analysis: NO3, COD, BOD, TOC, UV254…

UV water quality analyzers monitor key variables such as COD, BOD, TOC, nitrates, etc., in real-time. Their advanced technology provides reliable accuracy to enable proactive management of water resources, reducing operating costs and ensuring regulatory compliance.

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Our UV measurement options come in probe, analyzer and hand-held format.

Explore our comprehensive range including an underwater UV254 probe, STACSENCE probe, STAC2 multi-wavelength on-line UV analyzer, and PASTEL UV hand-held device. Available in various versions for different measurement scopes, contact us to find the best option to meet your measurement needs in terms of natural water, urban or industrial sanitation.


UV254 STACSENSE measuring probe

Discover our UV254 probe to monitor SAC254, COD, TOC, & BOD

STAC2 Analyzers full UV spectral range: NO3, COD, BOD, TOC, SS

Discover our range of multi-spectral on-line UV analyzer

PASTEL UV full UV spectral hand-held range: NO3, COD, BOD, TOC, SS

A simple and efficient alternative to multi-spectral UV hand-held devices

Why measure SAC254?

SAC254, also known as the Spectral Absorption Coefficient, specifically measures absorption at a wavelength of 254 nanometers. This measurement is often used in the field of water analysis to evaluate the concentration of dissolved organic components. The wavelength of 254 nm is particularly sensitive to certain organic compounds, in particular those related to natural organic matter in water. By monitoring absorption at this wavelength, SAC254 indicates water quality in terms of organic matter. This is critical in assessing water drinkability or monitoring water quality in industrial processes and wastewater treatment facilities.

What are the benefits of UV analyzers?

UV analyzers are a must in water quality analysis as they offer substantial benefits. Their main advantage lies in how quickly results are provided to enable real-time monitoring and immediate reaction to fluctuations. These instruments perform direct measurements, avoiding the need for reagents, by accurately assessing the concentration of organic matter at a wavelength of 254 nm using STACSENSE, or at multiple wavelengths using STAC2. The reliability of this technology lies in its resistance to clogging and low maintenance, providing stability over time. Versatile UV analyzers can be used in a variety of contexts, from drinking water to industrial water. They use a widely accepted technology with acknowledged accuracy in measuring variables such as COD, nitrates, and many others, thus helping protect water resources and the safety of industrial processes.

How do I calculate COD, TOC and BOD from a UV measurement?

The Chemical Oxygen Demand (COD), Total Organic Carbon (TOC) and Biological Oxygen Demand (BOD) are calculated indirectly from a UV measurement at 254 nm. UV absorption at this wavelength is often correlated with the concentration of dissolved organic matter to give indirect estimates of COD, TOC and BOD. It is important to emphasize that these estimates are rapid indicators and may vary depending on the specific composition of the organic matter present. While these correlations provide a quick assessment of water quality, specific methods are recommended for regulatory or water treatment applications that require greater accuracy.

STAC2 Installation scaled


"Maintenance of a STACSENSE UV254 probe is essential to ensure optimal operation. Here are some key steps to follow: Regular Cleaning: Remove any organic or mineral deposits that may impair light transmission from the UV lens. Calibration: Calibrate the probe to the manufacturer's specifications for accurate measurements over time. Temperature Management: Make sure the probe is operating within the recommended temperature ranges to ensure high performance. Proper Storage: Follow the manufacturer's instructions regarding long-term storage, particularly if soaking solutions are required. Staff Training: Make sure personnel are properly trained to perform maintenance tasks, including cleaning, calibrating, and replacing components.
Preventive Maintenance: Set up a corrective maintenance program to anticipate potential problems and extend the life of the probe. Regular maintenance ensures on-going reliability of the UV probe."

The STAC2 analyzer, based on UV-Vis technology, evaluates water quality by measuring the absorption of UV light at various wavelengths (190-800 nm) in the ultraviolet-visible spectrum. The absorption of water, which is normally transparent to UV light, is influenced by any organic compounds. Fitted with a Xenon lamp emitting a UV spectrum, the analyzer measures the absorption of organic compounds at specific wavelengths, creating a unique fingerprint of the water. This fingerprint is correlated with quality variables such as BOD, COD, TOC, nitrates, via mathematical coefficients and a specific calculation method called deconvolution. STAC2 provides innovative advanced real-time monitoring to assess water chemistry and ensure water quality.

The STAC2 multi-wavelength UV Analyzer offers exceptional versatility by providing up to 4 measurement channels (4 separate samples) to simultaneously analyse critical variables such as COD, BOD, TOC, nitrates and SS. In addition to these advanced features, the STAC2 comes with two dedicated blank control channels control, ensuring the cleanliness of the tank and cleaning solution to minimise maintenance requirements. This ingenious design aims to minimize maintenance operations, resulting in major cost savings. By monitoring key variables in real time and simplifying cleanliness checking, STAC2 offers a cost-effective, low-maintenance option ensuring maximum operational efficiency.

UV analyzers operate with most types of water, but there are a few factors to be taken into consideration. Highly turbid waters may affect the accuracy of measurements, as turbidity can absorb UV light. Turbidity compensatory mechanisms may be required in such cases. In addition, substances that readily absorb UV light, such as certain organic compounds, may influence the results. Our UV analyzers may need adjusting or correcting to take these substances into account. It is important to select an appropriate UV analyzer for the specific properties of the water to be tested and to take into account the specific conditions of the location to ensure accurate measurements. As specialists in UV measurement, our teams will support you with all your projects.

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