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THE BASICS OF METAL DETECTING
A hobby metal detector is intended for locating buried metal objects. When
searching for metals, underground or on the surface, you have the following
challenges and objectives:
1. Ignoring signals caused by ground minerals.
2. Ignoring signals caused by metal objects that you do not want to find,
like pull-tabs.
3. Identifying a buried metal object before you dig it up.
4. Estimating the size and depth of objects, to facilitate digging them up.
5. Eliminating the effects of electromagnetic interference from other
electronic devices.
Your ALPHA metal detector is designed with these things in mind.
1. Ground Minerals
All soils contain minerals. Signals from ground minerals can interfere with the
signals from metal objects you want to find. All soils differ, and can differ
greatly, in the type and amount of ground minerals present. The detector
incorporates an automated ground-balancing feature which will eliminate
false signals from most types of soils.
There is no user adjustment. If you experience false signals from severe
ground conditions, such as highly mineralized soil found in many gold
prospecting locations, or red-clay soils, reduce sensitivity.
2. Trash
If searching for coins, which will induce higher tone sounds, you want to
ignore items like aluminum foil, nails, and pull-tabs. These undesirable
items induce lower tones. You can listen to the sounds of all objects
detected, and decide on what you want to dig up. Or you can eliminate
unwanted metals from detection by using the DISCRIMINATION feature.
3. Identifying Buried Objects
Different objects induce different tones (high, medium, low) and are classified
on the display screen in different categories from left to right.
TARGET IDENTIFICATION
Targets are identified both audibly and visually as follows:
1. Different pitch tones for different types of metals
2. An illuminated icon within the target category best describing it.
AUDIO TARGET IDENTIFICATION:
Tones identify targets as follows:
LOW TONE
Ferrous objects, such as iron and steel, like nails and tin cans.
Smallest-sized gold objects and steel bottle caps
MEDIUM TONE
Newer pennies (post-1982 are minted from zinc)
Larger gold pieces, small brass objects, and most bottle screw caps.
Foil, pull-tabs, nickels and most recent-vintage non-US coins.
HIGH TONE
Silver and copper coins, large brass objects
Older pennies (pre-1982 were minted from copper)
Dimes, quarters, half-dollars, silver dollars
Susan B. Anthony and Sacajawea dollar coins
Flattened aluminum cans (with a stronger signal than a coin)
Audio Target Identification (ATI) classifies metals into three categories.
LOW TONE
Nails & Steel Bottle Caps,
& Small Gold
MEDIUM TONE
Pull Tabs, Nickels, Smaller &
Larger Gold, Zinc Pennies
(Post 1982), Many screw caps
HIGH TONE
Copper, Silver & Brass
Copper Pennies (Pre 1982)
