General Information - PRESTON PRESSURE PS-500 User And Maintenance Manual

CHAPTER 1

GENERAL INFORMATION

Description of the PS-500 Pitot-Static Test Box
The PS-500 Air Data, pitot-static test box is a digital display tester used to test aircraft
altimeters, airspeed indicators, pitot-static systems, and other vacuum and low-pressure
devices. This test box incorporates transducer sensor technology that is largely immune
to the failures and costly repairs associated with analog instruments.
The PS-500 is battery powered and portable. The vacuum and pressure sources are
derived from independent internal pumps, and each has its own reservoir, thus
eliminating the complexity and maintenance of an additional pressure/vacuum selector
valve. The tester can simulate pressure and vacuum suitable for up to 35K ft and 650
Knots.
The PS-500 measures altitude in feet and meters. Airspeed is displayed in miles-per-hour,
kilometers-per-hour, and knots. Vacuum and pressure are also selectable in various units
of measure, including inches Hg, milliBars, mm Hg, and Psia.
 Pressure Sensors
The sensors used in the PS-500 test box are proprietary transducer sensors. The pitot
sensor is not a differential pressure sensor as is most typically used. Instead, the pressure
information from the static sensor is sent digitally to the airspeed's microprocessor,
where it is subtracted mathematically from the pitot pressure, thus giving the differential
pressure value. This design eliminates several components, with their associated costs
and maintenance.
The sensor has an overpressure rating of 10 times the normal range.
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