Ultraviolet, blue and IR optical radiation pose a potential health hazard for both human skin and eyes. Common sunburn, photokeratitis (welder‘s eye) and burning of the retina or cornea are examples of injuries that can occur due to overexposure. Because of the dramatic increase in global UV radiation and the cumulative nature of the harmful effects, the risk of UV exposure by artificial sources in combination with solar UV is a concern. The efficiency of protective devices like sun creams, UV blocking fabrics and sunglasses are the subjects of study. Photobiologists, industrial hygienists, health and safety officers measure UV irradiance (W/m²) and irradiance dose (J/m²) of global and other artificial sources of optical radiation in the laboratory, field and in the work place in order to ensure safe levels and to study both the harmful and helpful effects.

The major UV health hazards:
    - The spectral weighting function for the acutely harmful effects of UV radiation, was developed by the American Conference of Governmental Industrial Hygienists (ACGIH) and the International Commission on Non-Ionising Radiation Protection (ICNIRP). 
    - The typical symptom of UV erythema is acute skin inflammation caused by UV radiation (sunburn). It used to be thought that erythema was only caused by radiation components in the UV-B range of wavelengths.
    - Radiation in the "blue" part of the spectrum from 380 to 700 nm (effectively 380 to 550 nm) triggers photochemical reactions, if the photon energy in the radiation is high enough, converting chemically unstable molecules into one or more other molecule types. Classified under Retinal and Blue Light Hazard.

Different methods of assessing optical radiation hazard may be employed by industrial hygienists, health and safety officers and health care personnel. The method used will depend on the radiometer and the functions it offers and what level of information is required.

• CW measurements indicate the instantaneous effective irradiance impinging on the subject or target measured in eff W/cm² or W/m². By multiplying the effective irradiance by the expected length of time of exposure, the daily dose of radiation can be calculated and compared to the recommended guidelines.
• Dose or irradiance summed over time is a measure of subject radiant exposure in the energy units of eff J/cm² or J/m². Many radiometers offer a dose function but since the measurement is based on exposure over time this method may prove impractical for an eight-hour period due to detector size and subject discomfort.
• Datalogging of irradiance with the ability to internally calculate dose provides the very best means of assessing exposure levels. But in order to be successful the entire detection system and electronics must be compactly packaged small enough to be worn by the subject without connecting cords or interfering with everyday tasks. Datalogging provides a true profile of individual exposure over any length of time. With computer interface the data can be plotted for easy detection of when exposure levels peak and when safe levels are exceeded.

To meet the many varied application demands, Gigahertz-Optik has developed detectors and dosimeters accordingly. Because Gigahertz-Optik is actively involved in the „Thematic Network for Ultraviolet Measurements“ funded by the Standards, Measurements and Testing program of the Commission of the European Communities, the detector and instrument designs are at the highest available level:

 Additional information from our Products section: 
        Multi-Channel Illuminance / Effective Irradiance Light Detectors
        Single-Channel Effective Irradiance Light Detectors
        Possible Optometer: X1₁, X9₁₂, P-9710
        Dosimeter: X-2000
        
 Additional information from our Tutorials section: VI.1. Phototherapy and Radiation Protection

 or contact us