Engine indicating systems Flashcards
What are the primary required engine instruments?
-Tachometer
-Oil pressure
-Oil Temperature
-Manifold pressure
-Coolant temperature
What do instruments measure?
-Mechanical movement
-Pressure
-Temperature
-Voltage
-Resistance
What does absolute pressure measure?
A force compared to a total vacuum, or absolutely no pressure.
What does gage pressure measure?
The difference between the pressure to be measured and the atmospheric pressure.
What does differential pressure measure?
The difference between two pressures.
What instrument can be used to indicate negative pressure?
Bellows or diaphragm
What is pitot pressure?
Ram air pressure used to measure airspeed and is taken into one side of the bellows
Static pressure
Ambient air pressure surrounding the aircraft is vented into the other side of the bellows
What is a transducer?
It converts the energy of the pressure into electrical energy, which can be interpreted by the computer.
What does a bourdon tube measure?
Pressure ant temperature
What is a thermocouple?
Loops of wire that are different metal types. Voltage is induced between two junctions that is proportional to the temperature difference between them. Voltage can be measured and converted to temperature.
What are the metals in a thermocouple?
Chromel and alumel
How is power produced by a reciprocating engine determined?
-Amount of pressure driving the pistons down
-Number of power strokes per minute
What does a tachometer measure in a turbine engine?
Percent of rated engine RPM.
How are most electric tachometers based?
3-phase electric synchronous motor
What are the cases for electrically operated instruments and instruments containing a rotating magnet made of?
Steel or iron
What is a synchroscope?
An instrument that indicates whether two or more rotating devices, such as engines are synchronized.
What is engine pressure ratio measurement?
The amount of thrust produced by the engine
Where is pressure measured in a turbine engine?
-Compressor inlet
-Pressure after the last turbine stage
What is EPR ratio?
Turbine discharge total pressure to the compressor inlet total pressure
What measures fuel on a recip engine?
A fuel flow meter
What is used to measure fuel flow on a fuel injected recip engine?
A pressure gauge
If a fuel injector becomes clogged. Does the pressure gauge read higher or lower?
Higher
How is fuel flow measure in a turbine engine?
Mass as in pounds per hour
