The New York herald., 1922-01-01
NEW INSTRUMENT
LOCATES TROUBLE
Complete Description of a Re-
markable Westinghouse De->
vice for Car Owner.

Motorists will be interested in the
Sparkle recently placed on the market
by the Westinghouse Lamp Company,
165 Broadway. which is an instrument
for the location of electrical faults in the
Eigh tension portion of automobile and
similar ignition systems.
The essential part of the Sparkle is
a small Geissler tube, filled with Neon
gas. one OF the five inert gases con-
tanned in the atmosphere. OF which 1t
forms about one part in 10000.
A distinguishing feature of the inert
or noble gases is the readiness with
which they will pass an electric dis
charge. even at very high pressures,
provided that no chemically active gases
are present as impurities. 1t is this
property which makes these gases ap-
rlicable to device like the Sparkle.
Neon is chosen because of its striking
appearance when passing a discharge
Most gases in a Geissler tube give off
blush or whitish light, and the intensity
of this light is quite small, except when
very powerful discharge passes. Neon,
however. even when passing quite small
currents, sends out a striking fiery red
light easily recognized even in the pres
ence of strong sunlight
The Geissler tube in the Sparkle is
about two inches long and about one
quarter outside diameter. The central
part of the tube is somewhat CONSTRUCTED
so as to increase the brilliancy of the
discharge, which takes place between
two electrodes of nickel wire welded to
lead-in wires having the same coefficent
of expansion as the glass Of which the
tube is made
The bulb is mounted inside a protec-
tive casing Of black hard rubber 11-1G
inch outside diameter and 71s inches
long A window placed in the side of
the casing opposite the narrow part of
the Geissler tube enables the discharge
to be seen. This window is made mar
row, so that even in bright sunlight the
discharge tube Is somewhat shaded,
making the red glow more striking. To
avoid any danger of breakage and dis
charge, the tube Is held in position in
side the casing by thick washers of soft
material
II the brass tip is applied to any
source of alternating or discontinuous
potential of sufficient magnitude. and
the other end of the casing held in the
hand sufficient current will flow to
cause the tube to show a red glow.
1t has been found that when the
Sparkle is used to test the condition of
the spark plugs in gasoline motor a
crackeu ana SnOrter plug or one heaV-
lily coated with carbon will. at best,
cause dull irregular flicker in the
tube, while a perfect plug will cause a
bright easily visible glow. pulsating
regularly. II. however. the gap be-
tween the points of the plug is too
wide the glow will be exceedingly
bright and the bulb in the Sparkle will
begin to glow before actual contact is
made between the brass contact tip and
the top of the plug. sometimes up to
a half inch away, while a plug whose
gap Is correct should only cause ap-
preciable light In the Sparkle when
actual contact is made.
The Sparkle is equally valuable In
testing any part of the ignition system
following back along the wires to the
distributor coil and megneto.
Any defect will register in the Spark
c even In the wires themselves, because
insulation is no barrier TO the sensitive
indicator of the Sparkle.