This part of ISO 8130 specifies a method for the
calculation of the lower explosion limit of a coating
powder, i.e. the minimum concentration of the
coating powder in air which will form an explosive
mixture. It is based on the knowledge of the gross
calorific value of the product, as determined by the
method described in ISO 1928, or on the gross
calorific values of the constituents of the product.
Reliable methods for the measurement of this
quantity require the use of special apparatus which
may not be readily available, A method for
determining the explosion indices of combustible
dusts in air is given in ISO 6184-1. This method is,
however, very intricate, requires considerable
expertise and is expensive. The calculation method
leads to lower explosion limits which have been
proved in practice to be satisfactory when applied to
coating application plants.
NOTE 1 With powders that are not flammable, such as those of
the poly(vinyl chloride) type, the method may nevertheless give a
value for the lower explosion limit in air. Thus, any
underestimation of an explosion risk is effectively avoided.
NOTE 2 The calculation used in this International Standard is
based on the following assumptions:
a) that material exists in the form of a molecular dispersion;
b) that there is complete combustion of the meterial to the
highest oxidation level;
c) that there is an adiabatic type of reaction;
d) that the flame temperature for the composition with which
the minimum concentration for explosion in air is attained
is 1 000 °C.
BS EN ISO 8130-4:2010 Referenced Document
ISO 1928:1976 Solid mineral fuels — Determination of gross calorific value by the calorimeter bomb method, and calculation of net calorific value
ISO 6184-1:1985 Explosion protection systems; Part 1 : Determination of explosion indices of combustible dusts in air
ISO 842:1984 Raw materials for paints and varnishes; Sampling