Engine Instrument Systems Flashcards
In what units is the tachometer for a reciprocating engine calibrated?
In hundreds of RPM
In what units is the tachometer for a gas turbine engine calibrated?
In percent of the ENGINES RATED TAKEOFF RPM
Where does the manifold pressure gauge used on an aircraft reciprocating engine pick up the pressure it measures?
From the intake manifold of the engine
What are two types of pick ups used for measuring the cylinder head temperature of a reciprocating engine?
The thermocouple can be embedded in a gasket that is installed under the spark plug of the hottest running cylinder, or it can be in a bayonet that is held against the cylinder head by a spring.
Why do most engine oil pressure gauges have a restrictor in the line between the engine and the instrument?
The restrictor damps out pressure pulsations in the oil to keep the needle from oscillating
What is used to measure the fuel flow of an opposed, fuel injected recip engine?
A pressure gauge that measures the pressure drop across the injector nozzles
What is indicated if the needle of a ratiometer type oil temperature indicator pegs to the high side of the dial as soon as the aircraft master switch is turned on?
There is an open in the bulb circuit that causes the instrument to see an infinite resistance. The higher the resistance in the bulb circuit, the higher the temperature indication
What type of indicating system is used to measure the exhaust gas temperature of a turbine engine?
A set of thermocouples arranged in an averaging circuit. These thermocouples are installed in the tail pipe of the engine
What should a thermocouple type cylinder head temperature indicator read when the engine is not operating?
The temperature of the outside air
How does a torquemeter actually measure the torque produced by an engine?
A torquemeter is actually an oil pressure gauge. The pressure it measures is produced in a torque sensor and is proportional to the amount of strain in the torsional shaft that drives the reduction gears of the turboprop engine
What two pressures are measured to get the Engine Pressure Ratio of a turbojet engine?
The turbine discharge total pressure and the compressor inlet total temperature system
Of what two materials are the thermocouples made that are used in a turbine engine exhaust gas temperature system?
Chromel and Alumel
What kind of mechanism is normally used to measure oil pressure in a reciprocating engine?
A bourdon tube mechanism
What is measured by the tachometers used on a two spool gas turbine engine?
The N1 tachometer shows the RPM of the low pressure compressor, and the N2 tachometer shows the RPM of the high pressure compressor
Does the tachometer of a geared reciprocating engine indicate the speed of the crank shaft or the propeller shaft?
The speed of the crankshaft
