Striking Element : It has a hemispherical face of radius 10 mm,
made of Teflon, weighing 0.15 Kg.
Steel Tube : It has external diameter – 9mm, and thickness – 0.5
mm. Steel tube
is pivoted at its upper end in such a way that it
swings only in the vertical plane of
the axis of the striking
element. The design of the apparatus is such that a force
between 1.0 N to 2.0 N is applied to the face of the hammer to
maintain the pendulum in horizontal position. Striking Element is
rigidly fixed to the lower end of the steel tube.
The appliance is held against a solid wall of bricks, concrete or the
like, and the test apparatus is so arranged that the pivot of the
pendulum is vertically above the point of impact of the hammer.
The striking element is then allowed to fall from such a
height of 250 mm. Three such blows are applied to every part of
the enclosure which is likely to be weak, including handle,
levers and the like, but excluding single lamps and their covers if
these do not protrude from the enclosure by more than 3 mm or
have a surface not exceeding 3 cm (square).