UV254 Spectrophotometer

Overview

This project aims to develop a low-cost UV spectrophotometer for assessing water filter effectiveness and measuring dissolved organic matter in drinking water.

Commercial UV spectrophotometers used for water testing typically cost over $2,000. Our goal is to build a working prototype costing under $100 in parts that can be constructed and used in community workshop settings.

Why UV254?

UV absorbance at 254nm wavelength is a reliable indicator of dissolved organic matter (DOM) in water. This measurement is particularly useful for:

• Testing the effectiveness of biochar and activated carbon water filters
• Monitoring filter breakthrough (when filters need replacement)
• Assessing water quality without expensive laboratory tests

The Science

Research by Dr. Josh Kearns and colleagues has shown that UV254 measurement can serve as a surrogate for detecting harder-to-measure contaminants. Some contaminants adsorb more easily to filters than others - by tracking the easier-to-measure dissolved organic matter, we can infer when more stubborn contaminants might be breaking through.

Current Development

We're building on published DIY spectrophotometer designs, developing custom PCBs for the UV LED emitter and photodetector, and testing against commercial instruments to validate accuracy.

To find out more, visit: Edge Collective - UV Spectrophotometry