Narco Avionics AR850 - 2.4.6 Correspondence Tests

NARCO AVIONICS AR850
2-12 7/03
FIGURE 2-5 P101 PIN ASSIGNMENTS
2.4.6 Correspondence Tests
A data correspondence check between automatically reported pressure altitude
and the pilot's altitude (aircraft altimeter) reference is required.
The AR850 Altitude Reporter shall correspond to the aircraft altimeter
within ±125 feet (38.1 meters) when the pressure datum is set for 29.921
inches of mercury absolute (1013.25 millibars).
2.4.6.1 Test Equipment Requirements
Any test equipment capable of "reading " the code generated by the AR850
and/or replies transmitted by the transponder is acceptable.
The most convenient equipment is the self-contained "ramp check" type
available from several manufacturers which "reads" the altitude in the ABCD
code and/or feet.
The pneumatic equipment must be of high quality and precision and be capable
of exercising the AR850 and aircraft altimeter over the range of -500 to
+30,700 feet. The equipment must be capable of holding an altitude long
enough to obtain accurate data to confirm correspondence.
2.4.6.2 Test Procedure
1. Allow AR850 to warm up 15 minutes before beginning the test.