Apparatus For Testing Durability Of Markings On Rating Labels , IEC 60730-1-Figure 8

Apparatus for testing durability of markings on rating labels , IEC 60730-1-Figure 8

Technical parameters:

Indelibility of markings
A.1 Markings on controls shall be adequately indelible for safety and are therefore classified according to the requirements for indelibility:
A.1 .1 Markings which are not mandatory within the requirements of this standard.
A.1 .2 Markings which are mandatory within the requirements of this standard but which are not accessible to the final user when the control is mounted or installed in the equipment.
These markings have to be sufficiently resistant to removal to withstand the manual handling in the control manufacturer's factory after final inspection, being packed and transported to the equipment manufacturer's factory, and handled during installation. Additionally, the
marking shall remain legible in the presence of any vapour or other contaminant likely to be present.
A.1 .3 Markings which are mandatory within the requirements of this standard and which are accessible to the final user of the equipment after the control is mounted or installed as for normal use.
These markings, in addition to being resistant to the handling, etc., described in A.1 .2, have also to withstand the rubbing and handling expected during the use of the equipment.
Markings on knobs, etc., shall survive the continual handling and rubbing as a result of manual actuation. Other markings should be resistant to cleaning, polishing and the like.
A.1 .4 Compliance with the requirements for indelibility of markings classified according to A.1.2 and A.1.3 is checked by the tests of Clause A.2 or A.3 using the apparatus shown in Figure 8.
The principal part consists of a disc of hard white buffing felt, 65 mm in diameter and 7,5 mm thick. This is locked against rotation and is arranged to move across the surface to be tested with a stroke of 20 mm and to exert a measurable force on this surface. The standard test shall be 12 strokes (i.e., rotations of the eccentric) and shall take approximately 15 s.
During the tests, the appropriate part of the buffing disc is covered with one layer of white absorbent lint with the nap surface external.
A.2 Compliance with the requirements for indelibility of markings classified according to
A.1.2 is checked by the following tests:
A.2.1 The markings under consideration shall withstand drops of detergent standing on the marked surface for a period of 4 h. At the end of this period, the detergent "scab(s)" shall be removed by a very fine spray of warm water (40 ± 5) °C or by lightly wiping with a damp cloth.
A.2.2 The sample shall then be allowed to dry completely in an ambient room temperature of (25 ± 5) °C.
A.2.3 The sample shall then be rubbed in the apparatus of Figure 8, using dry lint and a weight of 250 g measured as indicated.
A.2.4 The sample shall then be rubbed using water-soaked lint and a weight of 250 g.
A.2.5 If the shape or position of marking is such that it cannot be bleached or rubbed with this apparatus (for example, by recessing the marked surface) then the tests of A.2.3 and A.2.4 are not applied.
A.2.6 At the conclusion of these tests, the marking shall still be legible.
A.3 Compliance with the requirements for indelibility of markings classified according to
A.1.3 is checked by the following tests:
A.3.1 The marking under consideration shall be rubbed in the apparatus of Figure 8 using a dry lint and a weight of 750 g.
A.3.2 The marking shall then be rubbed in the apparatus using a water-soaked lint and a weight of 750 g.
A.3.3 The marking under consideration shall then withstand drops of detergent standing on the marked surface for a period of 4 h. At the end of this period, the detergent "scab(s)" shall be removed by a very fine spray of warm water (40 ± 5) °C or by lightly wiping with a damp cloth.
A.3.4 After being allowed to dry it shall be rubbed in the apparatus using a detergent soaked lint and a weight of 750 g.
A.3.5 After surplus detergent has been shaken off it shall be rubbed in the apparatus, using a petroleum spirit soaked lint and a weight of 750 g.
A.3.6 For the tests of A.3.1 to A.3.5 the thickness of the buffing disc may be progressively reduced from 7,5 mm in order that the marking may be reached and rubbed. However, the minimum thickness of the buffing disc shall be not less than 2,5 mm. If the thickness of the
buffing disc is reduced the weight of 750 g shall be reduced in linear proportion.
A.3.7 At the conclusion of these tests, the marking shall still be legible.