TB 9-4920-363-24
CAUTION
Some TI models do not have independent case leak valves for
both altimeter and climb rate indicators. When calibrating
altimeter indicator on these models, avoid exceeding range of
climb rate indicator while adjusting TI for altimeter
indications.
(4) Slowly adjust PRESSURE INCREASE and DECREASE control valves until
pneumatic pressure standard indicates zero (zero feet altitude). Adjust knob (on front of TI)
for a reading of 29.92 on TI barometric indicator. If TI ALT meter does not indicate zero
feet, perform b below.
(5) Slowly adjust TI PRESSURE INCREASE and DECREASE control valves
until TI ALT meter indicates -500 feet. Pneumatic pressure standard will indicate between
-470 and -530 feet.
(6) Slowly adjust TI PRESSURE INCREASE and DECREASE control valves
until TI ALT meter indicates -1000 feet. Pneumatic pressure standard will indicate
between -970 and -1030 feet.
NOTE
If local elevation exceeds 500 feet above sea level, pressure
instead of vacuum must be applied to TI to obtain indications
below local elevations.
(7) Position TI controls as listed in (a) through (g) below:
(a) PRESSURE INCREASE and DECREASE control valves as necessary to
obtain atmospheric pressure.
(b) POWER switch to OFF.
(c) PRESSURE selector control valve to OFF.
(d) PRESSURE INCREASE and DECREASE control valves to open position.
(e) VACUUM selector control valve to ALTIMETER 50,000 FT RATE OF CLIMB.
(f) VACUUM INCREASE and DECREASE control valve to closed position.
(g) POWER switch to ON.
(8) Slowly adjust VACUUM INCREASE and DECREASE valves until TI ALT
meter indicates 500 feet. Pneumatic pressure standard will indicate between 465 and 535 feet.
NOTE
Tap indicator gently to reduce friction.
(9) Repeat technique of (8) above for TI altimeter indications listed in table 3.
Pneumatic pressure standard will indicate within limits specified.
(10) Position TI controls as listed in (a) through (d) below:
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