The stable corona discharge has found use in a large number of
electrostatic
applications and one of their important properties is the inception voltage which
can be
easily and accurately measured. The empirical Peek's law which yields the corona
inception
field is previously made in standard air for wire-to-cylinder geometry and used for
many
years. However, the generalisation of this law, which at present derives from
Hartmann's
physical-mathematical model, requires new measurements with varying air physical
parameters.
This classical law expresses the inception field at the anode surface in function of
the
anode diameter, the related air density and the humidity. New measurement method of
the
positive DC corona-current voltage characteristics have been introduced in a
wire-to-cylinder
and wire-to-plane systems. Remarkable similarities between these basically different
systems
are shown in this paper and the steady corona-current voltage characteristics are
described
by the Townsend's square law in a large range of related air density. The
normalization
factor at air density equals unity and the humidity function suggested by the model
are also
determined from the measurements. The model values of the inception field at the wire
surface
agree with measured values in both wire-to-cylinder and wire-to-plane systems.