you are here: start> contents> overview Overview of the student materials Sensors booklet Description of Student Materials Practical activities Notes for students Introduction   Introduction: sensors & frontier science Uses the Cassini-Huygens mission to Saturn to illustrate how scientists develop and make use of sensors to support research; the two sensors chosen illustrate aspects such as the use of underlying science and key procedures such as calibration, and provide an introduction to some of the activities in the Sensors pack. Thermal Sensors Using a thermistor as a temperature sensor: Using a multimeter on a resistance range with a thermistor Using a thermistor temperature sensor with a potential divider network and a voltmeter to measure temperature Using a thermistor with a potential divider network and datalogging equipment to measure temperature. Using the band-gap LM35DZ temperature sensor Using the band gap sensor with a multimeter Using the band gap sensor with datalogging equipment. About thermal sensors Types of thermal sensor, how they work and what they are used for. Light Sensors Using a light dependent resistor (LDR) to measure illuminance: Preliminary activity: Matching power supply voltages to a bulb’s illuminance Using a multimeter on its resistance range with the LDR Using an LDR with a potential divider network and a voltmeter to measure illuminance Using an LDR with a potential divider network and datalogging equipment to measure illuminance Using a photodiode to measure Percentage Reflectance Uses two different LEDs and two different reflecting surfaces. About light sensors Use of light sensors on satellites; Photovoltaic cell, photodiode, phototransistor and light dependent resistors as common types of sensors for light and infrared radiation Sound Sensors Using a microphone to investigate crispness Comparing waveforms and frequency spectra (Two versions: one using Multimedia Sound, the other using PicoScope on DrDAQ) About sound sensors Types of microphone; how a microphone works; Examples of use Force Sensors Using the conductive foam sensor to make a weighing machine Using the conductive foam sensor with a multimeter on its resistance range Using the conductive foam sensor in a potential divider network Using the conductive foam sensor in a potential divider network with datalogging equipment Using a piezoresistive sensor to make a weighing machine Using the piezoresistive force sensor with a multimeter / millivoltmeter Using the force sensor with datalogging equipment About force sensors Use of light sensors on satellites; Photovoltaic cell, photodiode, phototransistor and light dependent resistors as common types of sensors for light and infrared radiation Flow rate Sensors Using a propeller dynamo/generator to measure liquid flow rates Mean e.m.f or voltage method using the propeller dynamo/generator with a multimeter Mean e.m.f or voltage method using the propeller dynamo/generator with datalogging equipment Mean current method using the propeller/dynamo generator with a multimeter Using a turbine with a magnetic pickup to measure liquid flow rates Mean frequency method using the turbine with a multimeter or frequency meter Mean frequency method using the turbine with datalogging equipment About flow rate sensors Use of flow rate sensors in real life situations; How the propeller dynamo/generator meter works; How the turbine meter with a magnetic pickup works. Position Sensors Using a rotary potentiometer to sense the position of a model aileron Using the rotary potentiometer with a multimeter or voltmeter Using the rotary potentiometer with datalogging equipment About position sensors Use of rotary potentiometers as position sensors in aircraft; incremental and absolute shaft encoders as other types of position sensors Potential Dividers Selecting the best value resistor to use with a sensor in a potential divider circuit Using a potential divider with a sensor Key ideas, plus a set of worked examples and questions leading to selection of the best resistor.   |