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1665. A Compact Version of
Milikan's original apparatus which has been designed to in
corporate an aligned light source and optical system on the same
base as the parallel plate cell, enabling the determination of the
electronic charge'E, with a minimum of setting-up time.
A three-way potentiometer unit gives control over the direction and
magnitude of the electric field strength between the cell plates
when used with H.T. power supply, or any 300 V d.c. source.
Terminals provided on the potentiometer enable the use of a
voltmeter to indicate the potential difference between the plates.
The cell, light source and microscope are mounted on a sheet metal
base which is fitted by three spring-loaded screws, two of which are
adjustable. to a sub-base having a clamp to fit in a retort stand
rod.
The cell, having plates separated a distance of 5mm by an insulating
collar, is blackened, may easily be dismantled for cleaning and is
surrounded by a plastic draught shield.
The light source consists of a lens-fronted, low-wattage lamp which
passes light into the cell via a plastic rod, thus ensuring that the
cell interior receives maximum illumination with negligible heat
transfer. The lamp may be supplied from the 6.3V terminals on the
power supply unit or from a 6V battery.
The focusing microscope has a square-ruled graticule for drop
velocity measurements and vertical and lateral alignment screws.
A glass jet rubber bulb atomiser is provided together with a supply
of oil. The atomiser may be operated by one hand.
Also supplied is a fine wire focusing object which, when not in use,
can conveniently be retained by sponge rubber pads on the under side
of the plastic lid of the draught shield.
Millikan Oil-Drop Apparatus as specified with Potentiometer unit
leads, Atomiser, Bottle of silicon oil, and instruction.
Spare parts or Accessories
a) Atomiser
b) Oil Silicone
c) Lamp.
d) H. T. Power supply to provide D. C. voltage to charge the oil for
the lamp. Voltmeter 100-300 Volts DC. |
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