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Reading Comprehension
Metal Detectors
Have you ever seen a man with a headset pointing a long pole at the ground on the beach?
If so you might have seen a person using a metal detector. People use these devices to find metal.
Metal detectors make magnetic waves. These waves go through the ground. The waves change when they hit metal then it beeps. This lets the person with the device know that metal is close.
The first metal detectors were meant to help miners. They were big and cost a lot of money. Although they use a lot of power, they didn’t work well. People kept trying to make them better.
Nowadays metal detectors are smaller, light and cheap. That’s why people bring them to the beach. People can look for rings in the water, as well as look for phones in the sand. But they usually find junk though. Metal detectors also protect people. They help to keep guns out of some places:
Airports, courthouses and, schools. They also help guards look for weapons. Guards use special wands to find metal on a person.
These devices save lives in other ways too. During wars, people plant bombs in the ground. When the war ends, they don’t clean up their messes. This is unsafe for the people who live in those places. Others use metal detectors to find bombs. They remove them and help the people. These devices also make clothes safer. It sounds funny, but it’s true. Most clothes are made in big factories.
There are lots of needles in these places. Needles break from time to time. They get stuck in the clothes. They would poke people trying them on. They don’t though. That’s because our clothes are scanned for metal. Isn’t that nice?
Metal detectors make the world a safer place.