Quiz 2 compiled for BBL

Strain Gauges/Load Cells

• Principle of operation: Change in electrical resistance
• Main application: Measuring force and weight

LVDT

• Primary function: Measuring linear displacement

Accelerometers

• Measure: Vibration of motion of a structure
• Principle of operation: Newton's Second Law of Motion
• Capacitive MEMS Accelerometer detects acceleration by exploiting the movement of a seismic mass, resulting in a capacitance change

Piezoelectric Effect

• Principle: Generating electric charge from mechanical stress

Water Flow Sensors

• Primary function: Measuring the rate of flow of liquids
• Mechanism: Mechanical and electrical subsystems

Rain Sensors

• Output: Both analog and digital
• Principle of operation: Optical sensing

Barometric Pressure Sensors

• Also known as: Pressure transducer, Manometer
• Primary function: Monitoring atmospheric pressure

Manometers

• Primary function: Measuring the pressure of a fluid
• Significance in environmental studies: Measuring atmospheric pressure and other environmental gases

RTDs

• Principle of operation: Change in electrical resistance with temperature
• Primary application in industrial settings: Monitoring and controlling temperature

Thermistors

• Characteristic: High sensitivity and nonlinearity
• Suitable for: Lower temperatures

Thermocouples

• Primary advantage: Wide temperature range and simplicity
• Characteristic: High sensitivity and linearity
• Suitable for: Higher temperatures

Temperature Sensors

• Most commonly used: Thermocouple
• Purpose of reference junction: To maintain a constant temperature

TEG

• Principle of operation: Seebeck effect

LM35 Temperature Sensor

• Output voltage: Proportional to temperature in Celsius

TEC

• Purpose: To cool or heat electronic devices

Bimetallic Thermostat

• Characteristic: Expands at different rates when heated

Photovoltaic Cells and Sensors

• Primary function of a photovoltaic cell: to convert light energy into electrical energy
• Device used to amplify the photoelectric current: phototransistor or photodiode
• Characteristic of a photodiode that enables it to produce both voltage and current: P-N junction or light-sensitive exposed junction

Proximity Sensors

• Primary function of a proximity sensor: to detect the presence of an object
• Types of proximity sensors:
  • Inductive proximity sensor: useful for detecting metallic objects
  • Optical proximity sensor
  • Capacitive proximity sensor: can detect both metallic and non-metallic objects
  • Magnetic proximity sensor
  • PIR sensor: detects motion and triggers alarms in security systems

Radiation and Sensors

• Radiation used by some proximity sensors to detect objects: infrared radiation (IR)
• Primary function of a Hall Effect sensor: proximity switching and positioning
• Primary function of a laser diode: produces a concentrated and coherent light beam

Gas Sensors

• Primary function of RF diodes: efficiently control and manipulate RF signals
• Primary function of electromechanical gas sensors: detect the presence of gases in the atmosphere
• Principle behind the operation of Electrode type salinity sensor: measures changes in conductivity

Turbidity and Salinity Sensors

• Primary function of a Turbidity Sensor: determines the particle concentration and purity of a solution
• Primary function of LDRs: detects or senses light intensity
• Principle behind the operation of Infrared Spectroscopy breathalyzers: measures the absorption of infrared radiation by alcohol molecules

Heartbeat and Fuel Cell Sensors

• Primary function of an optical Heartbeat Sensor: measures heart rate by detecting changes in blood volume
• Principle behind the operation of Fuel Cell Breathalyzers: electrochemical reactions

Magnetometers and Transducers

• Primary function of a magnetometer: measures the direction, strength, or relative change of a magnetic field
• Primary function of a transducer in an ultrasonic sensor: converts electrical signals to ultrasonic sound waves
• Primary function of an E-Nose device: detects the smell of complex volatiles

Color Sensors

• Primary function of a color sensor: determines the color of an object by processing electrical signals converted from light reflected from the object
• Primary function of a magnetometer: measures the direction, strength, or relative change of a magnetic field