10-12-2012, 02:00 PM
Sensor Technologies
[attachment=43229]
Phase Linearity
Describe how well a system preserves the phase relationship between frequency components of the input
Phase linearity: f=kf
Distortion of signal
Amplitude linearity
Phase linearity
Sensor Technology - Terminology
Transducer is a device which transforms energy from one type to another, even if both energy types are in the same domain.
Typical energy domains are mechanical, electrical, chemical, magnetic, optical and thermal.
Transducer can be further divided into Sensors, which monitors a system and Actuators, which impose an action on the system.
Sensors are devices which monitor a parameter of a system, hopefully without disturbing that parameter.
Categorization of Sensor
Classification based on physical phenomena
Mechanical: strain gage, displacement (LVDT), velocity (laser vibrometer), accelerometer, tilt meter, viscometer, pressure, etc.
Thermal: thermal couple
Optical: camera, infrared sensor
Others …
Classification based on measuring mechanism
Resistance sensing, capacitance sensing, inductance sensing, piezoelectricity, etc.
Materials capable of converting of one form of energy to another are at the heart of many sensors.
Invention of new materials, e.g., “smart” materials, would permit the design of new types of sensors.
Specifications of Sensor
Accuracy: error between the result of a measurement and the true value being measured.
Resolution: the smallest increment of measure that a device can make.
Sensitivity: the ratio between the change in the output signal to a small change in input physical signal. Slope of the input-output fit line.
Repeatability/Precision: the ability of the sensor to output the same value for the same input over a number of trials
[attachment=43229]
Phase Linearity
Describe how well a system preserves the phase relationship between frequency components of the input
Phase linearity: f=kf
Distortion of signal
Amplitude linearity
Phase linearity
Sensor Technology - Terminology
Transducer is a device which transforms energy from one type to another, even if both energy types are in the same domain.
Typical energy domains are mechanical, electrical, chemical, magnetic, optical and thermal.
Transducer can be further divided into Sensors, which monitors a system and Actuators, which impose an action on the system.
Sensors are devices which monitor a parameter of a system, hopefully without disturbing that parameter.
Categorization of Sensor
Classification based on physical phenomena
Mechanical: strain gage, displacement (LVDT), velocity (laser vibrometer), accelerometer, tilt meter, viscometer, pressure, etc.
Thermal: thermal couple
Optical: camera, infrared sensor
Others …
Classification based on measuring mechanism
Resistance sensing, capacitance sensing, inductance sensing, piezoelectricity, etc.
Materials capable of converting of one form of energy to another are at the heart of many sensors.
Invention of new materials, e.g., “smart” materials, would permit the design of new types of sensors.
Specifications of Sensor
Accuracy: error between the result of a measurement and the true value being measured.
Resolution: the smallest increment of measure that a device can make.
Sensitivity: the ratio between the change in the output signal to a small change in input physical signal. Slope of the input-output fit line.
Repeatability/Precision: the ability of the sensor to output the same value for the same input over a number of trials