PC/CP300 Electronics Laboratory II

Sensors and Signal Conditioning

Classifications based on

• R. Pallàa-Areny and J. G. Webster, Sensors and Signal Conditioning (2nd ed), John Wiley & Sons, Inc. 2001.
• J. G. Webster, The Measurement, Instrumentation and Sensors Handbook, CRC Press, 1999.

Sensor Type	Examples [see Note 1]	Signal Conditioning [see Note 2]
Resistive	potentiometers strain gages force sensing resistors resistive temperature detectors (RTDs) thermistors magnetoresistors light-dependent resistors (LDRs) resistive hygrometers resistive gas sensors liquid conductivity sensors	measurement of resistance voltage dividers potentiometers thermistors Wheatstone Bridge: balance measurements Wheatstone Bridge: deflection measurements differential and instrumentation amplifiers interference
Reactance Variation and Electromagnetic	capacitive variable capacitor differential capacitor inductive variable reluctance eddy current linear variable differential transformers (LVDTs) variable transformers: synchros, resolvers, inductosyn magnetoelastic and magnetostrictive Wiegand and pulse-wire saturation core superconducting quantum interference devices (SQUIDs) electromagnetic sensors based on Faraday's law Hall effect sensors	ac Bridges carrier amplifiers and coherent detection phase sensitive detectors specific signal conditioning for capacitive sensors synchro-to-resolver converters digital-to-resolver converters resolver-to-digital converters
Self-Generating	thermoelectric - thermocouples piezoelectric pyroelectric photovoltaic electrochemical	chopper and low-drift amplifiers electrometer and transimpedance amplifiers charge amplifiers impedance amplifiers noise in amplifiers noise and drift in resistors
Digital and Intelligent	position encoders incremental position encoders absolute position encoders resonant sensors quartz resonators SAW sensors vibrating wire strain gages vibrating cylinder sensors digital flowmeters variable oscillators sinusoidal oscillators relaxation oscillators variable CMOS oscillators conversion to frequency, period, or time domain voltage to frequency conversion direct quantity to frequency conversion direct quantity to time duration conversion direct sensor-microcontroller interfacing digital tachometer intelligent sensors Hall Effect sensor	communication systems for sensors current telemetry simultaneous analog and digital communication sensor buses
Other Sensing Methods	semiconductor junction based thermometers based on semiconductor junctions magnetodiodes and magnetotransistors photodiodes position-sensitive detectors (PSDs) phototransistors semiconductor junction nuclear radiation detectors MOSFET transistor based charge-coupled and CMOS image sensors fiber optic sensors infrared distance measuring sensors ultrasonic sensors biosensors

Note 1: items in bold are sensors that we have in stock and can be used for the project

Note 2: items in bold are signal conditioning topics to be covered in the lectures