A guard who always
watches the
temperature.

Temperature Sensors

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#06

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I check and let you know if the temperature gets hot or cold.
Temperature sensors are also called “thermistors” sometimes.

The Power of Temperature Sensors

Letting you know if it gets hot or cold.

Machines stop working when they get too hot or cold.
Temperature sensors measure the temperature outside and inside the machine and report them to you, so that you can use the machine safely and in the right way.

An illustration of a temperature sensor at work. It can measure temperature changes, like when ice melts and becomes hot water.

The Secret of the Power of Temperature Sensors

The electric current tells us the temperature!

The amount of electric current that can go through a temperature sensor changes with its temperature.
More can go through at higher temperatures, and less at lower temperatures.
That means that we can see it’s “hot” when more electric current is flowing.
And we can also tell it’s cold when less electric current is flowing!

An illustration of how electric flow changes. Less electric current flows when it is cold, and more flows when it is hot.

Friends of Temperature Sensors

Pictures of lead-type temperature sensors

Many sizes and ways of measuring

We call small electronic parts “chip types” and large ones used in construction “lead types.”
Lead-type temperature sensors look nice because they have long legs.
There are even temperature sensors that keep circuits safe by stopping the electric current when it gets hot.

Trivia

What are the units?

We measure how hard it is for electricity to get through a temperature sensor in units called “Ω” (ohms).
For example, a circuit might not let much electricity through at 10 Ω when it’s cold, but it could let more through at 1 Ω when it gets hot.

Think it out!

QUESTION

The answer is 2, air conditioners!
They have powers to change the room, making it hotter or colder.

Find the Temperature Sensor!