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Sensorex UV Transmittance Measurement

UV Transmittance, also known as ultra violet transmittance, refers to the percentage of light that passes through a water sample at the wavelength of 254 nm. UVT relates to the organics, colloidal solids, and suspended particles that absorb and scatter this UV light wavelength.

The amount of UV light absorbed by the sample is known as the UV Absorbance (expressed as A254). Absorbance and transmittance are relevant by this logarithmic function A = log 10 (1/T).

Why is UVT Measurement Necessary?

The measurement provides valuable insight to the suspended solids and organics content in the water sample, and is a parameter used in the dose calculation for UV disinfection systems.

How is UVT Transmittance Measured?

Ultraviolet (UV) light, at the wavelength of 254 nm, is passed through a path of a 1cm water sample. Compared to a light intensity being measured in pure water and displaying a percentage, the intensity of the light is measured beside a photodiode.


UV Transmittance Monitor, Online

The UVT-LED-SW Online UV Transmittance Sensor provides reliable UVT measurements for UV disinfection optimization.

Ideal for continuous monitoring of open channel wastewater UV disinfection, the UVT-LED-SW features an LED light source that lasts up to 5x longer than traditional mercury lamps. Our patented automatic cleaning and calibration system reduces fouling and drift, so technicians don’t have to waste time servicing the units daily. Available with inline or submersioninstallation kits (see “What’s Included” below).

  • Simple connectivity: Direct 4-20mA output (no transmitter or controller required)
  • Effortless installation: Select a mounting kit designed for your needs, whether installing a new system or retrofitting
  • Reliable continuous monitoring: Patented automatic cleaning & calibration system
  • No Lamp Changes Required: High-performance UV-C LED technology eliminates mercury lamps
  • Extended Lifetime