TESTS CARRIED OUT IN THE PHOTOMETRIC LABORATORY
TEST 1: VISIBILITY AT DAWN
This test measures luminance, i.e. how much light an object hit by a beam of light returns in low light conditions, such as at dawn or dusk. It was carried out by the optical engineer Selene Carrara. The beam is produced by an 80 lux lantern placed 15 m away, and all the measurements were taken under the same conditions: lantern distance and illuminance, divergence and distance of the photocells. The cd/m2 value, i.e. the luminous intensity expressed in candelas (cd) emitted in the direction of the observer from a given surface (m2) determines the result.
TEST 2: NIGHT “REFLECTION”.
The retroreflectors, this is the exact name of the visible reflective bands of eight when they are hit by a light, must reflect the artificial ray (car lights, street lamps, etc.) that strikes in the same direction from which it comes and nowhere else, with a maximum tolerance of 1° 30′, so as not to annoy other road users. Under the same conditions as test 1, the candles reflected for a given surface were measured in relation to the Lux emitted by the lantern: cd/(lux*m2).
TEST 3: FLUO CLOTH QUANTITY
To detect the distance at which an object is visible, the data obtained in tests 1 and 2 are fundamental, but not sufficient. A further evaluation is needed, i.e. the measurement of the quantity of “fluorescent” fabric present on the garment in question and its type: the CevLab technicians explained to us that a perforated garment, albeit microscopically, loses a small part of its luminance, and even more the so-called 3D fabrics.