Ultraviolet (UV) radiation constitutes a portion of the electromagnetic spectrum from 100 to 400 nm, and is further subdivided into three wavelength ranges: UV-A (315 to 400 nm), UV-B (280 to 315 nm) and UV-C (100 to 280 nm). Much of the UV-B and all of the UV-C wavelengths from the sun are absorbed by the Earth’s atmosphere. There are also many artificial UV light sources available that output a select wavelength range or offer a broadband UV radiation source.
Most UV sensors designed for sunlight measurements are sensitive to UV radiation in the UV-A and UV-B ranges. Apogee Instruments UV Sensors detect UV radiation from 250 to 400 nm and are calibrated in photon flux units of micromoles per square meter per second (µmol m-2 s-1). The output can also be expressed in energy flux units of watts per square meter (W m-2, equal to Joules per second per square meter).
Typical applications or UV sensors include:
- UV radiation measurement in outdoor environments (sensor is not recommended for long-term continuous outdoor deployment)
- laboratory use with artificial light sources (e.g., germicidal lamps)
- monitoring the filtering ability and stability of various materials