Operating and Technical Descriptions
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2.
MECHANICAL SPECIFICATION
2.1.
Dimensions
Camera: 27cm x 17cm dia. (excluding pistol grip and visor)
Voltage Stabiliser Unit: 18cm x 6.5cm x ll.5cm
2.2.
Weight
Camera: (including harness, muff, visor and pistol grip) 3.0kg
Voltage Stabiliser Unit: (less batteries) 0.5kg
2.3.
The camera case comprises a two part polycarbonate moulding
retained by a breech type locking ring.
The voltage stabiliser unit is a polycarbonate moulding.
3.
OPERATING MODES
The signal is proportional to the rate of change of the temperature of
the pyroelectric target and decays within 10 seconds of exposure. To
obtain a continuous signal from a stationary object a shutter is used to
obscure the target at field rate. Alternatively the image - or camera -
may be moved or panned.
3.1.
Shutter
A rotating shutter is incorporated into the front of the camera. It is
synchronous in rate and phase with the camera scanning beam. The
images obtained are alternately inverted in polarity. They are
synchronously re-inverted and balanced in the video channel to give
continuous positive images. Shading correction circuits aid balance
between the signals and minimise flicker.
4.
LINE FLYBACK GAS PEDESTAL
The ion pedestal within the tube is enhanced by increasing the beam
current during line flyback, i.e. by pulsing Gl positively. By this means a
larger signal is obtained from the tube. An automatic circuit detects and
regulates the ion pedestal.
5.
OPERATING PROCEDURE
Plug the battery cartridge into the voltage stabiliser ensure the
connection between the stabiliser and camera is made, then switch on.
A satisfactory operating voltage is confirmed by observing that the
LEDs in the viewing window illuminate. A circular image will now be
obtained after a target discharge period and the camera chopped or
panned operating mode may be selected as required.
