Photoluminescent glow in the dark products vary in how bright they are and how long they last.
In general, brighter, longer lasting glow signs and tape cost more than lower grade glow options.
Luminescent glow in the dark products have a glow value assigned based on how brightly they glow. The higher the number the brighter the glow. Two measurements are taken, one at 10 minutes and one at 60 minutes. These values are expressed in terms like 20/3, 55/8, 150/22 and 450/60. The glow will be visible for several hours and up to a few days.
Luminance is measured with a photometer. Each item is exposed to the same amount of light – 93 foot candles = 1000 Lux for 5 minutes. These test methods are described in ASTM E2072-04 Standard, ASTM E2073-02 Test Method and DIN67510 Part 1. After activation, the luminance is measured in millicandela per square meter (mcd/m2) at 10, 60 and 120 minutes to calculate the decline of light produced.
Our standard and NYC photoluminescent tape and signs are visible for 6 to 10 hours in the dark.
The IBC/UL1994 150/22 photoluminescent markings are visible for 35 hours in the dark.
For power 450/60 and higher performing photoluminescent markings are visible for several days.