Electrometer Gauge.
An absolute electrometer (see Electrometer, Absolute) forming an
attachment to a Thomson quadrant electrometer. It is used to test the
potential of the flat needle connected with the inner surface of the
Leyden jar condenser of the apparatus. This it does by measuring the
attraction between itself and an attracting disc, the latter connected
by a conductor with the interior of the jar.
Electrometer, Lane's.
A Leyden jar with mounted discharger, so that when charged to a certain
point it discharges itself. It is connected with one coating of any jar
whose charge is to be measured, which jar is then charged by the other
coating. As the jar under trial becomes charged to a certain point the
electrometer jar discharges itself, and the number of discharges is the
measure of the charge of the other jar. It is really a unit jar, q. v.
Fig. 156. THOMSON'S QUADRANT ELECTROMETER.
Fig. 157. HENLEY'S QUADRANT ELECTROSCOPE.