Table of Contents Volume Contents ................................................... V Preface.................................................................. VII Acknowledgments................................................ IX Table of Contents ................................................ XV Aircraft Instrument Systems ............................10-1 Introduction..................................................................10-1 Classifying Instruments ...............................................10-3 Flight Instruments ....................................................10-3 Engine Instruments...................................................10-3 Navigation Instruments ............................................10-4 Pressure Measuring Instruments ..................................10-5 Types of Pressure .....................................................10-7 Pressure Instruments.................................................10-8 Engine Oil Pressure ..............................................10-8 Manifold Pressure.................................................10-9 Engine Pressure Ratio (EPR)................................10-9 Fuel Pressure.......................................................10-10 Hydraulic Pressure..............................................10-11 Vacuum Pressure ................................................10-11 Pressure Switches ...............................................10-11 Pitot-Static Systems................................................10-12 Pitot Tubes and Static Vents...............................10-13 Air Data Computers (ADC) and Digital Air  Data Computers (DADC) ...................................10-16 Pitot-Static Pressure-Sensing Flight Instruments...10-16 Altimeters and Altitude.......................................10-16 Vertical Speed Indicator .....................................10-22 Airspeed Indicators.............................................10-24 Remote Sensing and Indication .................................10-26 Synchro-Type Remote-Indicating Instruments ......10-26 DC Selsyn Systems.............................................10-27 AC Synchro Systems ..........................................10-28 Remote Indicating Fuel and Oil Pressure  Gauges ................................................................10-29 Chapter 10 Mechanical Movement Indicators..............................10-29 Tachometers ...........................................................10-30 Mechanical Tachometers ....................................10-30 Electric Tachometers ..........................................10-30 Accelerometers.......................................................10-33 Stall Warning and Angle of Attack (AOA)  Indicators................................................................10-33 Temperature Measuring Instruments .........................10-36 Non-Electric Temperature Indicators.....................10-36 Electrical Temperature Measuring Indication........10-37 Electrical Resistance Thermometer ....................10-37 Ratiometer Electrical Resistance  Thermometers .....................................................10-38 Thermocouple Temperature Indicators ..................10-39 Turbine Gas Temperature Indicating Systems ...10-40 Total Air Temperature Measurement .....................10-42 Direction Indicating Instruments ...............................10-43 Magnetic Compass .................................................10-43 Vertical Magnetic Compass ...................................10-45 Remote Indicating Compass...................................10-46 Remote Indicating Slaved Gyro Compass  (Flux Gate Compass)..............................................10-46 Solid State Magnetometers.....................................10-47 Sources of Power for Gyroscopic Instruments ..........10-47 Vacuum Systems ....................................................10-48 Venturi Tube Systems.........................................10-48 Engine-Driven Vacuum Pump............................10-49 Typical Pump-Driven System.............................10-50 Twin-Engine Aircraft Vacuum System  Operation ............................................................10-51 Pressure-Driven Gyroscopic Instrument Systems..10-52 Electrically-Driven Gyroscopic Instrument  Systems...................................................................10-52 Principles of Gyroscopic Instruments........................10-53 Mechanical Gyros...................................................10-53 Solid State Gyros and Related Systems .................10-54 Ring Laser Gyros (RLG) ....................................10-55 Microelectromechanical Based Attitude and  Directional Systems ............................................10-56 Other Attitude and Directional Systems .............10-56 XV