Pressure Sensors College of Engineering（压力传感器工程学院）.pptVIP

Pressure Sensors Absolute – A Sensor That Measures Input Pressure in Relation to a Zero Pressure. We Will Use the Absolute Pressure Sensor to Calculate Altitude. Differential – A Sensor That Is Designed to Accept Simultaneously Two Independent Pressure Sources. The Output Is Proportional to the Difference Between the Two Sources. We Will Use the Differential Pressure Sensor to Calculate Indicated Airspeed. Determining Altitude From Absolute Pressure Determining Indicated Airspeed From Differential Pressure The equation for converting the pressure difference to airspeed is: Velocity in mph Dynamic pressure in Newton / meters ^2 or Pascals Density in kg / meter ^3 Standard density of 1.225 kg / M ^3 (*note* -- the air density can change with weather, and altitude) Pressure Sensor Basics Classes of Motorola Pressure Sensors Maximum Minimum Pressure Parameters The Motorola MPX4115 Absolute Pressure Sensor The Motorola MPX5050D Differential Pressure Sensor Additional Reference Sites for Motorola Pressure Sensors * The equation for converting pressure to altitude is: Where pressure is in KPa Altitude is in feet above the zero pressure reference level The zero pressure level in Lexington, KY as of last night was 99.7 Kpa /brdata/PDFDB/docs/AN1318.pdf Uncompensated Pressure Sensors – These standard, low cost, sensors permit manufacturers to design and add their own external temperature compensation and signal conditioning networks. Compensated Pressure Sensors – These sensors have built in temperature compensation and signal conditioning. Integrated Pressure Sensors – These integrated sensors have built in temperature compensation and signal conditioning just like the Compensated Pressure Sensors. The Integrated Pressure Sensors are designed specifically to use with microcontroller applications and have an easy one wire interface to hook to the A/D port on a microcontroller. For each three classes there are a variety of (A)bsolute and (D)ifferential pressure s