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Home , Metal detector

FOR CHILDREN AGED 5 TO 7 YEARS To be used with adult supervision AT ALL TIMES

Metal Detector

WHAT’S IN THE BOX?

Use the items detector provided to explore Metal practice ‘’ (washer) the detection of and how this Magnifying lens can help you find Note pad and pencil hidden ! String and pegs (8 sets) • Please return the box with all equipment clean and Small digger packed as you found it. Discovery notes • Report any missing or damaged items to the staff.

Spark! Discovery Boxes are an initiative of Children’s Discovery www.childrensdiscovery.org.au Anti-tank mine designed to damage or destroy vehicles including tanks during What is a Metal WW2 Detector? A is just that – a tool that can detect the presence of nearby metal. Metal As metal detectors are really useful tools for locating metal hidden detectors are usually within rocks, or metal buried hand-held devices under ground, they are used a that can be moved lot in mining to find metal ores. slowly over the ground Being able to detect metal means or other surface. If they also have a use in security; detecting dangerous devices like metal is detected they landmines buried underground will give some kind of , or concealed on people buzzing sound, or move – security is one example. the needle on a dial. Metal detectors are also used by The closer the metal archaeologists to help find buried the louder the sound, metal tools and other artefacts, or higher the needle as well as hunters! There are small metal detectors you can moves. use to find pipes and wires hidden behind walls and floors in your house.

Metal detector finds a trove of medieval

2 Metal Detector

Alexander : Graham Bell: © Georgios | trying to find the Dreamstime.com bullet in James Garfield

History that he used in 1881 to try and locate a bullet that had been and engineers fired into the chest of the started playing around making American President, James machines to detect metals in Garfield. The good news is that rocks over 150 years ago. They the metal detector worked…but were very large and used up unfortunately the bullet could lots of battery power. not be found as the detector got Alexander Graham Bell was a confused by the metal springs in famous American inventor who the bed the President was lying developed a metal detector on at the time he got shot!

Metal Detector 3

Using Your Metal Detector Practice Your Sweep • In your box there is a metal When you are starting out as a detector set. ‘metal detector’, one thing you need • Turn the POWER knob toward to get right is learning the correct the ON position and the power way to swing the coil over the indicator light will light up. ground – also known as sweeping. • Continue to turn the knob You will want to keep the coil (the until you hear a long “beep” bottom of the detector) close to the and see the indicator lights ground and at the same distance. flash. This means keeping the coil parallel to the ground at all times. • Turn the knob slowly back toward the OFF position Maybe try pretending the metal until just after the unit stops detector is a vacuum cleaner – but beeping. This means the metal hovering above the ground at all detector is now ready for use! times. Practice in your yard, or at a park. Be adventurous, and try exploring over lumpy, bumpy, rocky ground – but do make sure you’re also looking where you’re going!

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How does a metal detector work? Metal detectors are based on the science of The detection of metals is very electromagnetism. important, for example at airport security. Look out for metal detectors You may already be familiar next time you visit an airport or even with magnets, and how a shop. Shops use special detectors they are attracted to metals to stop people taking things they’ve (usually metals made with not paid for! ). You may also be familiar Try this! with batteries, and how runs through conductors (made of metal) to create an electric circuit. Gently wave the metal detector over your body, does it change What might be news to its sound at any point, such as you is that where you find near any metal zips, buckles or a you will usually watch? Ask permission to try this also find electricity. on others in your family! You can use electricity Test your metal detector over to make magnetism some coins (or start with our and magnetism to practice coin/washer). Find make electricity. This somewhere outside where you can ‘bury’ the coin about 2cm means that electricity underground or hide under some and magnetism are two leaves. Ask someone to come parts of the same thing: and find your treasure using the ELECTROMAGNETISM. metal detector. Make sure you find ALL your coins!

Metal Detector 5

An electromagnet ... As you sweep the detector over the ground, you make the magnetic is a simple device that can be field move around too. If you move made by wrapping a coil of metal the detector over a metal object, the wire around a metal nail and moving creates (or hooking it up to a small battery. “induces”) an electric current in Connect the circuit – and your the metal. nail will become a magnet. We know that if we have electricity moving in a piece of metal, it must create some magnetism as well. So, when you move a metal detector over a piece of metal, the magnetic field coming from the detector causes another magnetic field to appear around the metal. It’s this second magnetic field, A generator is a device for making around the metal, that the detector (“generating”) electricity and works picks up through a second coil by spinning a large coil of inside the of wire in its head (known as the magnetic field of a large magnet. receiver coil) that’s connected to a The spinning action can be created loudspeaker. by boiling water so that steam pushes the coil around, or using The closer you move the wind to spin giant blades connected coil to the piece of metal, the to the coil. A motor works in the stronger the magnetic field the opposite way. They use electricity to transmitter coil creates in it, the spin a motor, which can be used to stronger the magnetic field the metal run washing machines and vacuum creates in the receiver coil, the more cleaners. current that flows in the loudspeaker, and the louder the noise. A simple metal detector contains a coil of wire (wrapped around OK, that was tough, now go out and the circular head at the end of the find some treasure! handle) known as the transmitter coil. When electricity flows through More information: https:// the coil, a magnetic field is created www.explainthatstuff.com/ all around it. metaldetectors.html

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Be Scientific • Move slowly and listen out for a beep coming from the metal Once you get the hang of metal detector (avoid noisy areas!). detecting, you can start going When you hear a beep, stop and around your neighbourhood (with an sweep the area slowly until you’re adult always present) and hunt for sure you have a ‘find’. Use the treasure…such as coins (coins are digger to carefully dig the area always being dropped). (make sure you have permission It’s a good idea to now start or it’s ok to dig – see Code of behaving scientifically in your hunt. Practice). You might have to Try using the notepad and pencil sweep the Metal Detector over to make a basic map of your yard, any mound of have dug out of the park or any area you are going ground as well as the hole – to metal detecting. see if you have moved the ‘find’. Now, each time you discover • Use the magnifying lens to take a something, make a note on your closer look at your find. Again, you map. You may soon see a pattern of can act scientifically by making a your best sites. note about the object you found; maybe there’s a date on the coin? Some other helpful tips for metal Also make a note on your map. detecting in a park or beach: • Make a study of your hunting site; where are people hanging about? Where is the grass or sand more trampled? This indicates where people often travel and can increase your chance of finding objects. • Before you start your hunt, maybe set up a grid pattern using string and pegs (there is some in the box to get you started). Working with a grid will help you avoid searching the same areas over again, and make sure you don’t miss important areas that may be full of treasure! 7

Code of Practice for Metal Detecting Look out for Metal Being a responsible metal Detectors detector means following our own rules (or Code of Conduct). Some The science behind metal basic rules include: detectors is common in security devices like you see at . • Ask permission – always ask These detect items that should permission if you want to detect not be taken onto an airplane. on private property. Similar technology can now also • Fill in your holes. detect non-metallic items. • Respect private property and You may have noticed a special do not disturb/destroy any label stuck inside books you structures. can borrow from a library (or items in a shop) – these labels • Do not detect in National Parks contain small amounts of metal or Heritage Listed locations. which are detected as you • Check with your local Council pass by the detection antennas regarding detecting in Parks. near the library (or shop) entry. If not deactivated at the • Look for designated public counter, the label causes a short fossicking areas. electromagnetic signal that is received by the antennas and results in an alarm. REMEMBER When you are out with your metal detector you are an ambassador for the hobby. Be responsible and use every opportunity to explain your hobby to anyone who asks about it!

For assistance, further information or general feedback, please send an email to [email protected]

www.childrensdiscovery.org.au