DrDAQ is a versatile instrument that connects to the USB port of any PC. Using the supplied PicoScope software it can be used as an oscilloscope, spectrum analyzer and signal generator.
This experiment is adapted from the Advancing Physics course
(Activity 10D from chapter 2 : sensing).
You may be being watched! You are not alone! You are surrounded by sensors in everyday life. Many, like temperature sensors in washing machines and cookers, keep things under control so that you do not have to bother. Some like movement-sensitive systems on a house or block of flats, turn on the outside lights when you arrive home, or detect possible intruders. Some, like acceleration sensors in a car, wait to trigger off an air bag for your safety if the car should crash. Some, like the sensor in a television set or video, wait on your command.
By collecting data from four of the sensors on the DrDAQ data logger over a period of time, we could for example monitor a classroom for changes in light level, temperature, sound level and by using the change in resistance of the potentiometer also know whether the door had been opened or closed.
Start PicoLog collecting the data. At the end of the monitored period of time you will be able to analyze your results by clicking on View Graph. The four lots of data can all be displayed on one graph or separately. You will be able to see quite clearly how sound, light and temperature levels changed and how often the classroom door was opened and closed and at what time.
From this graph we can clearly see that the door was opened and allowed to close twice. Also sound levels correspond to activity within the classroom, temperature remained more or less constant and the increase and decrease in light levels correspond to blinds being opened and then closed again.
The example raises several important questions:
Some other things to think about:
What would you think about a ‘Smart House’ that could respond to changes in conditions? What would you want it to do? What would you not want it to do?
What sensors would be needed on a space craft, for an industrial robot or for an incubator for premature babies? What other examples can you think of?