Carbolum light calibration sources contain Carbon-14 activated phosphors, which are hermetically sealed in a cerium-stabilized optical glass envelope. An external black anodized aluminum housing is used to provide a unit with excellent shock resistance. The sources offer great luminance stability with a decay of less than 1% per year.
Carbolum sources are available in different emission colors, with very definite peaks in the whole range of the visible spectrum. Other phosphors having a very narrow peak or phosphors of great temperature stability are also available. In addition, it is possible to produce light standard sources, which contain a combination of different phosphors.
The light calibration sources are available in the luminance range between Nanocandelas/cm² and 10 mCd/cm², depending on the activity content and the type of phosphor which is used.
(1µcd/cm² = 3.14µL) The uniformity of the luminous surface is +/-7%.
The sources find use in photometric calibrations, photocells and photomultiplier tube calibrations, internal standards for thermo-luminescence, dosimetry evaluation equipment, celestial observations and night vision and low-level vision evaluations. Except for sources containing small quantities of by-product material, a specific license is required to obtain or possess light standard sources. The exempt amount of radioactive material in the United States is 100 µCi carbon-14 per source.
A calibration certificate may be delivered with each lot of light standard sources. The document contains specific data about the luminance, the activity content and the wavelength of the applied phosphor. An official certificate is available on request.