SENSORS FOR UV AND VISIBLE LIGHT APPLICATION NOTES

One watt of visible light corresponds to approximately 1019 photons. This large number of photons is the basis for the application of light and UV radiation as the surface interaction of the photons is usually limited to a few nm².

The scope of our UV sensors is just as varied, ranging from process monitoring, risk assessment, and job security to medical applications of UV lamps and UV LEDs. The following notes should assist in the selection of suitable sensors.

For process monitoring and dose control, the spectral range of the sensor depends basically on the UV application or usually the photoinitiator. UV spotlight sources such as the HP-120 reach irradiance in the range of a few W/cm². This is lower outside the spots or at a greater distance. The sensor should provide a wide measuring range of 0-2000 mW/cm² or more.

Low-pressure UV lamps and UVC amalgam lamps usually reach irradiances of less than 100 mW/cm² in the irradiation level. We recommend our sensors with a measuring range of 0 - 200 mW/cm².

The emission of UV LEDs occurs, for example, at 365, 385, 395, or 405 nm. A UVA+ sensor has been developed to measure UV LEDs. The latter has a wider spectral range. Measurements of UV LEDs in the area of the filter edge should be avoided since the smallest changes of temperature and charge fluctuations can cause high measurement errors.

For risk assessments and occupational or job safety, DIN EN 14255-1:2005 regulates the measurement and assessment of personal exposure to artificial optical radiation. DIN 14255-1 itself contains no limits. Limits are given in directive 2006/25/EC "Artificial Optical Radiation."

The sensors must be sufficiently sensitive for the measurements. To achieve this, select a sensor (e.g., UVA, UVB) with a measuring range 0 - 2 mW/cm². In accordance with 2006/25/EC directive, the UVA radiation limit is 104 J/m² for an eight-hour working day. This corresponds to continuous irradiance of 0.035 mW/cm². The maximum irradiance may be higher for short-term work, for example:
    Scope of work: Daily cleaning
    Duration: 10 min
    Exposure dose: HUVA = 104 J/m²
    Irradiance: 1.68 mW/cm²

Tip: UV systems should be designed so that the irradiance relative to the duration of the activity does not exceed the exposure dose. In general, installations should be checked if they continuously irradiate the worker with more than 1-2 mW/cm².

For medical applications, process safety and the calibration in the foreground are of most importance. Our sensors are durable and can be individually recalibrated. Repair and spare parts service is available for many years. Take advantage of our many years of experience as a calibration laboratory.

Applications with different UV lamps can be reproducibly measured with our radiometer sensors. A measurement of all spectral ranges at the same time is also possible (e.g., with the UVpad).