ISO 14889-2013 pdf free download

ISO 14889-2013 pdf free download.Ophthalmic optics — Spectacle lenses — Fundamental requirements for uncut finished lenses
Optique ophtalmique — Verres de lunettes — Exigences fondamen tales relatives aux verresfinis non détourés.
4.5.2.3 Dayllght use
The transmittance shall conform to the requirements specified in ISO 8980-3:2013, 6.3.3.
4.5.2.4 Driving in twilight or at night
The transmittance shall conform to the requirements specified in ISO 8980-3:2013, 6.3.4.
4.5.2.5 Relative visual attenuation coefficient (quotient) for recognition/detection of incandescent signal lights
The relative visual attenuation coefficient (quotient) shall conform to the requirements specified in
ISO 8980-3:2013, 6.3.5.
5 Test methods
5.1 General
All tests described in this International Standard are type tests.
5.2 Inflammability
5.2.1 Apparatus
The test device consists of a steel rod (300 ± 3) mm long and 6 mm nominal diameter, with a flat end face perpendicular to its longitudinal axis, a heat source and a thermocouple with a temperatureindicating device.
5.2.2 Procedure
Heat one end of the steel rod over a length of at least 50mm to a temperature of (650 ± 20)°C. Measure the temperature of the rod by means of the thermocouple attached at a distance of(20 ± 1) mm from the heated end of the rod.
With the rod positioned with its axis vertical, allow the heated face of the rod to rest under its own weight on the surface of the test sample for a period of not less than 5 s, and then remove the rod.
Repeat this test on a sample lens made from each material to be used. Carry out visual inspection to establish whether combustion continues after removal of the rod from the test sample.
5.3 Test for mechanical strength
5.3.1 Apparatus (see Figureji
5.3.1.1 Loading device
A steel ball of 22 mm nominal diameter is fastened to the lower end of a tube, the nominal length of which Is 70 mm. The loading mass shall be such that the force acting on the test specimen is (100 ± 2) N.
5.3.1.2 Specimen support
The specimen support consists of a steel supporting plate and a pressure ring. The upper face of the steel supporting plate and the lower face of the pressure ring are, by appropriate means, each fitted with a circular silicone rubber ring of(40 ± 5) IRDH having an inside diameter of(35 ± 0,1) mm and a nominal cross section of 3 mm x 3 mm.
If the specimen lens is of insufficient dimensions to enable its entire periphery to be adequately supported, a suitable adaptor sleeve shall be used.
The pressure ring has a mass of (250 ± 5) g.
NOTE I This pressure ring is necessary to ensure that the silicone seating presses securely against the upper surface of the specimen.
A sheet of carbon paper on top of a sheet of white paper is placed on the plane base of a cylindrical cavity in the supporting plate. The plane base of the cavity is located 1.5 mm below the surface to which the silicone ring is attached (assumed as being plane in this case), and parallel to it. In those cases where a supporting plate is designed to support a lens surface that is not rotationally symmetrical and therefore has a three-dimensional upper face to carry the silicone ring (see 5.3.22), the distance of 1,5 mm is measured from the lowest point of the edge of the cavity to the plane base of it.
NOTE 2 An alternative method may be used (e.g. a mechanical sensor to measure deformation) if shown to be equivalent.ISO 14889-2013 pdf free download.