What does UV/Vis spectroscopy measure?

UV/Vis uses light in the ultraviolet (200–380 nm) and visible range (380–780 nm). Coloured and optically active substances absorb characteristically. Typical parameters: SAC254 (organic load), turbidity (ISO 7027), nitrate, ozone and protein concentrations.

How is UV/Vis used in water analytics?

UV/Vis is a standard method in water monitoring. The spectral absorption coefficient at 254 nm (SAC254) is a sum parameter for organic load and correlates well with TOC. Inline probes enable continuous monitoring without sampling.

What is the difference between photometry and spectroscopy?

Photometry measures at one or a few fixed wavelengths; spectroscopy scans a broad wavelength range. Inline UV/Vis probes are typically spectrometers — providing full spectra and enabling simultaneous multi-parameter measurement.

What are the limitations of UV/Vis?

UV/Vis is sensitive to turbidity and particles that scatter light. In highly turbid media, probe configuration (path length) and calibration must be adapted. For complex matrices, chemometrics are required.

Measurement Principles

InlineOnlineAt-line

UV/Vis Spectroscopy

UV/Vis spectroscopy uses light in the ultraviolet and visible range to determine concentration, turbidity and organic substances.

Installation Types

Inline

Sensor directly in the process stream — no sampling, continuous real-time measurement.

Online

Automatic sampling via bypass loop — short analysis times, close to the process.

At-line

Sample analysed next to the line — flexible location, manual or automatic sampling.

Relevant Industries

Pharma & Bioprocess

Inline control of API synthesis using NIR spectroscopy

Environmental Monitoring

Continuous water body monitoring per EU Water Framework Directive

Food & Agriculture

NIR moisture, protein and fat determination on conveyor belts

Standards & Regulations

ISO 7027DIN EN 1484DIN 38404-3DIN 38405-D9

FAQ

Dusko Kadijevic | Publisher Analytic Journal | analyticjournal.com

Written March 2026. All content formulated in our own words, created with AI assistance.

© 2026 Analytic Journal / Dusko Kadijevic. Short excerpts with attribution and a link to analyticjournal.com are permitted. Full or substantial reproduction, including by AI systems or automated processes, requires written permission. Enquiries: info@analyticjournal.de