AS NZS IEC 61034.2:2017 pdf free
AS NZS IEC 61034.2:2017 pdf free.Measurement of smoke density of cables burning under defined conditions
The test sample shall remain in situ during the test as follows:
– individual test pieces or bundles of test pieces shall be bound together at the ends, and at 300 mm from each end, at which place they shall be clamped to the support by means of wire binders.
NOTE Depending upon construction, test samples prepared from small cables or flexible cables may be subject to movement during the test. In these cases, it is also recommended that the test pieces or bundles are bound with two turns of approximately 0,5 mm diameter wire in the centre and at every 100 mm each side from the centre.Alternatively, the test pieces or bundles may be tensioned at one or both ends by means of an appropriate device, for example a spring or a weight.
The tray containing the alcohol shall be supported above the ground surface to permit air circulation around and beneath the tray. The individual test pieces or the bundles of test pieces shall be laid touching in a horizontal position and centred above the tray so that the distance between the underneath of the test sample and the bottom of the tray is 150 mm±5 mm (see Figure 2).
Smoke consists of an aerosol of particles which can either be measured as a function of its gravimetric properties, its light obscuring properties, or a mixture of the two. This standard measures smoke as a function of light obscuring properties which are a function of the number and size of the particles in the light path. If the particles are considered as opaque, the capacity of the smoke to obscure light is related to the sum of the cross-sectional areas of the particles in the light path. It is measured in units of area, e.g. in square metres (m), and is called the extinction area, see A.1.2.AS NZS IEC 61034.2 pdf free download.