How do metal detectors work?
Metal detectors have a coil of wire inside them, called a transmitter coil. The coil sends out electromagnetic waves. When these waves hit a metal object, they are sent back to the detector. Different types of metal produce different readings, which an experienced metal detectorist can recognise.
What can they find?
Almost all kinds of metal objects can be found using a metal detector.
Passive metal detectors can detect ferrous metals (metals that contain iron) and active metal detectors can detect non-ferrous metals (metals that don't contain iron).
Over the years, spearheads, swords and coins have been found in the land around Lullingstone Roman Villa using metal detectors. This was done with special permission however and detecting is not permitted at any other time.
Recording Your Finds
Metal detecting can be a fun hobby but it has to be done responsibly.
Metal detectorists have to have full permission to detect on the land they want to explore. They must also report any objects they find which date to before around 1650 (just over 300 years ago) through the Portable Antiquities Scheme. This includes making a careful note of where the objects were found to help archaeologists map the finds accurately.
Why is metal detecting important?
Activity Idea
SCIENCE
Gather a range of metal objects and decide which kinds of metals they are made from.
Sort the objects into groups: those that would be detected using a passive metal detector and those that would be detected using an active metal detector.