Sensitive Altimeter; Altimeter - Piper ARROW III Service Manual

Trouble
Pointer cannot be reset
to zero.
Instrument reads very low
during climb or descent.
When any connections in the static system are opened for checking, system
must be rechecked per Part 23.1325.
10-31. REMOVAL AND REPLACEMENT. (Refer to Paragraph 10-74 of this section.)

10-32. SENSITIVE ALTIMETER.

10-33. GENERAL. The altimeter indicates pressure altitude in feet above sea level. The indicator has three
pointers and dial scale, the long pointer is read in hundreds of feet. the middle pointer in thousands of feet and
the short pointer in ten thousands of feet. A barometric pressure window is located on the right side of the
indicator dial and is set by the knob located on the lower left comer of the instrument. The altimeter consists of
a sealed diaphragm that is connected to the pointers through a mechanical linkage. The instrument case is
vented to the static air system and as static air pressure decreases, the diaphragm expands, causing the pointers
to move through the mechanical linkage.
10-34. TROUBLESHOOTING.
Trouble
Excessive scale error.
Excessive pointer
oscillation.
Revised: 2/13/89
CHEROKEE ARROW III SERVICE MANUAL
TABLE X-IV. RATE OF CLIMB INDICATOR (cont)
Diaphragm distorted.
Case of instrument
broken or leaking.
TABLE X-V. ALTIMETER
Improper calibration
adjustment.
Defective mechanism.
Cause
NOTE
Cause
2G1
Remedy
Replace instrument.
Replace instrument.
Remedy
Replace instrument.
Replace instrument.
INSTRUMENTS