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These resources have been reviewed and selected by STEM Learning’s team of education specialists for factual accuracy and relevance to teaching STEM subjects in UK schools.

Introduction to sensing fire with the Internet of Things

This one hour activity demonstrates how bimetallic strips work in smoke alarms.   Using the context of the Internet of Things and fire safety, students design, make, test and refine a sensor to detect heat and produce an electrical output that could be used to switch on a fire alarm.  This resource provides a demonstration and explanation of how a fire alarm works, as well as a quick activity demonstrating how bimetallic strips work.

There are three aspects to fire alarms which students consider:

1. some form of input (produced by the fire) that can be detected by a sensor

2. a processor that ‘decides’ if the alarm needs to sound

3. some form of output that alerts the people in the house, usually a loud noise

This input-process-output (IPO) structure is common to a vast number of internet of things (IoT) devices and control systems. In the practical activity, a bimetallic strip provides an input, an electrical circuit, when switched on, triggers the output, an alarm (in this case a buzzer).

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