This course is a combination of College Physics and Sensor.
Basis
Measuring System
Measurement refers to all operations aimed at determining the properties and magnitudes of objects.
Sensor
input: Physical Quantity/Chemical Quantity/Biomass
output: Electrical quantity
Performance and Evaluation
Bias
- From sensor's participation in environment.
- From improper use by the user or design flaws in the measurement system.
- dynamic derivation
Calibration
标定/校准
How to Select
- Holistic need principle
- High-reliability
- Cost-effective
Electric Sensor
Resistive Sensor
How to measure?
-
\(U=IR\)
-
Electrical bridge
Capacitive Sensing
\(C=\frac{\epsilon_0\epsilon A}{d}\)
Common Physical Effects
Elasticity
弹性
Spring: \(F=kx\)
Strain Parameters for Resistance
电阻应变效应
Piezoelectricity
压电效应
Photoelectric Effect
光电效应
\(E=h\nu-W_0\)
Optical Fiber
光纤
Electromagnetism
电磁效应
Faraday's law of electromagnetic induction
\(e=-W\frac{d\Phi}{dt}\)
\(e=WBlv_y\)
Hall effect
\(U_H=\frac{R_HIB}{d}\)
Magnetostriction
磁致伸缩效应
Ultrasonic Transducer
超声波传感器