Extra 200 - Page 239

CHAPTER 34
PAGE 5
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RA - FLUGZEUGBAU GmbH
SERVICE MANUAL EXTRA 200
PAGE DATE: 1. July 1996
34-10-02 Altimeter
The altimeter is designed to measure pressure changes of
the atmosphere by means of an aneroid capsule, the pres-
sure changes corresponding to changes in altitude. In this
instrument the shaft of pinion drives via gearwheels the
pointer shaft of the large pointer. Further gearwheels are
used to move the small pointer. The altimeter has a scale
marked in feet (ft.). Three pointers provide an indication of
the altitude; each full turn of the large pointer reads 1,000
feet, each full turn of the middle pointer 10,000 feet. By
turning the knob at the bottom left of the instrument, the
barometric pressure reading is set in millibars.
Barometric range: 946 thru 1050 millibars
Reading range: -1,000 thru 20,000 feet
Temperature range: -55°C thru +70°C
34-10-03 Airspeed Indicator
The airspeed indicator shows the speed of the aircraft
relative to the atmosphere. The pitot airspeed indicator
measures the difference between pitot pressure and static
pressure, the former being picked up by the pitot head at the
pitot location of the air flow and applied to the airspeed
indicator via tubing, the latter also being picked up by the
pitot head. The sensing element of the airspeed indicator is
an open diaphragm which senses internally the pitot pres-
sure and externally the static pressure, the difference be-
tween the two increasing with increasing speed. This
difference produces distortion of the diaphragm which is
translated to the pointer via a system of levers an gear-
wheels.
The reading of the airspeed indicator is in knots.
Max. operation altitude: 12,000 m
Operating temperature range: -30°C thru +50°C
FLIGHT ENVIRONMENT DA
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