3-9. Low Temperature Scale Error Test
For a period of not less than 6 hours prior to this test,
altimeter shall not have been subjected to any test
involving operation at other than atmospheric pressures.
Scale error (room temperature) test shall be repeated
except that temperature of the altimeter during test shall
be approximately __35 C (__31' F). Test points shall be
those given in table 3-5. Change in scale errors of this
test from corresponding scale errors of room
temperature test shall not exceed tolerances specified in
table 3-5. During this test, friction shall
instrument fails to meet this test, diaphragm must be
instrument readjusted. If the temperature compensation
adjustments are not disturbed, then the cold temperature
test is not required.
Table 3-5. Low Temperature Scale Error Test (-35C)
3-10. Case Leak Test.
3-11. Position Error Test
Connect static pressure connection of indicator to a
At normal atmospheric pressure, readings shall be
source of suction. Apply a suction sufficient to produce a
taken while instrument is being tapped lightly in each of
change of indication of pointers of approximately 18,000
several different positions. Change in pointer indication
feet. With source closed off during a period of 60
with change in instrument position shall not exceed 30
seconds, difference of indications shall not exceed 100
feet. If instrument fails to meet this test, it must be
feet. If a leak is indicated, check instrument and correct
for leak as described.
Change 6 3-4