To emit light, a product loaded with luminescent material must have been previously exposed to a dose of light (energy).This dose can be provided by sunlight or by an artificial light source whose emission spectrum and duration should be known to produce the expected visual effect on the product (luminance, color, remanence).
In addition to the applied radiation dose, the chemical composition and quantity of the phosphorescent materials contained in the products will be determinant for the desired effect.
PISEO has expertise in optics to develop specific artificial light sources based on monochromatic LED able to produce the energy radiation necessary to activate the phosphorescent phenomenon. In particular, PISEO has developed a test bench that combines a module equipped with UV LED and D65 LED and associated with a luminance camera. This device allows to simulate the light of day and to apply to the samples tested the desired energy doses and then to characterize the variation of the brightness levels (luminance) over time up to "the extinction”.
The device allows to carry out product benchmarks with a regular recording of the measure luminance after the application of variable energy doses according to the needs of the Customer.
Thanks to their knowledge of luminescent materials and the characterization of illumination systems, PISEO experts can also assist the Customer in defining the test program, in interpreting the results obtained and, if necessary, in improving the performance of the tested products through consulting on material formulation.
Note: Luminous decreasing are always compared regardless of the perception of the eye, but a red emission will be perceived much shorter than a green emission. The measurement of the luminance makes it possible to account for this physiological aspect. The luminance measurements realized by PISEO are based on the French standard NF X 08-050-1 Part 1.
Spectral and colorimetric measurements
Spectral and colorimetric measurements can also be done on samples using an Instrument Systems CAS 140 spectroradiometer.
WESTBORO PHOTONICS 5Mpx P501F camera:
Instrument Systems CAS 140 Spectroradiometer :