Cessna TURBO CENTURION T210M 1978 Pilot Operating Handbook page 180

SECTION 7
AIRPLANE
&
SYSTEMS DESCRIPTIONS
CESSNA
MODELT210M
If erroneous instrument readings are suspected due to water or ice in
the pressure lines going to the standard external static pressure source,
the alternate static source valve should be pulled on.
Pressures within the cabin will vary with open cabin ventilators and
windows. Refer to Sections 3 and 5 for the effect of varying cabin pressures
on airspeed and altimeter readings. ·
AIRSPEED INDICATOR
The airspeed indicator is calibrated in knots and miles per hour.
Limitation and range markings include the white arc (55 to 115 knots),
green arc (68 to 165 knots), yellow arc (165 to 195 knots), and a red line (195
knots).
If
a true airspeed indicator is installed, it is equipped with a rotatable ,-,.,
ring which works in conjunction with the airspeed indicator dial in a
manner similar to the operation of a flight computer. To operate the
indicator, first rotate the ring until pressure altitude is aligned with
outside air temperature in degrees Fahrenheit. Pressure altitude should
not be confused with indicated altitude. To obtain pressure altitude,
momentarily set the barometric scale on the altimeter to 29.92 and read . ~
pressure altitude on the altimeter. Be sure to return the altimeter baromet-
ric scale to the original barometric setting after pressure altitude has been
obtained. Having set the ring to correct for altitude and temperature, read
the true airspeed shown on the rotatable ring by the indicator pointer. For
best accuracy, the indicated airspeed should be corrected to calibrated
airspeed by referring to the Airspeed Calibration chart in Section 5.
Knowing the calibrated airspeed, read true airspeed on the ring opposite
the calibrated airspeed.
RATE-OF-CLIMB INDICATOR
The rate-of-climb indicator depicts airplane rate of climb or descent in
feet per minute. The pointer is actuated by atmospheric pressure changes
resulting from changes of altitude as supplied by the static source.
ALTIMETER
Airplane altitude is depicted by a barometric type altimeter. A knob
near the lower left portion of the indicator provides adjustment of the
instrument's barometric scale to the current altimeter setting.
VACUUM SYSTEM AND INSTRUMENTS
An engine-driven vacuum system (see figure 7-11) is available and
7-44