measure light intensity using photodiode equation

Measure light intensity using photodiode equation how to#

Incandescent, traditional (tungsten lamp) Typical relative UV levels from different light sources (updated and adapted from Michalski 2011 and Saunders 1989) Light Sources The UV range indicated in Table 1 includes values from both old and new fluorescent long tubes. In the last few decades, the amount of UV from fluorescent lamps has reduced significantly due to advances in technology. The sources of light with the highest UV content are the sun and high intensity discharge lamps, while the lowest is the light-emitting diode (LED) (blue pump type). Table 1 shows the possible ranges of UV emitted by different sources in units of microwatts per lumen ( µW/lumen). The relative value enables a quick comparison of UV content between illuminants, independent of light intensity.

Note that, while taking these measurements, it is preferable to have the UV meter facing the light source. It is the ratio of the amount of UV energy that a surface receives to the amount of visible radiation (lumens) from the same light source. The relative measure of UV is primarily used in heritage preservation and is almost unknown to professionals in other fields.

There are two common ways to measure UV radiation: compare the amount of UV energy relative to the light emitted by a source, or measure the absolute amount of UV energy an object receives over its surface.

Measure light intensity using photodiode equation how to#

Refer to CCI Note 2/1 Ultraviolet Filters for further information about UV damage and how to filter UV from a light source. This Note discusses different ways to measure UV and provides guidelines to estimate its potential impact on a collection. Minimizing the exposure of UV on a collection is important due to the cumulative damage it can cause to the colour and structure of materials. ( PDF Version, 466 KB) Ultraviolet (UV) Radiation