Also, push slowly forward with about half the search coil diameter each
time to ensure that the search coil scanned the detected ground
without any omissions. It was wrong to shake the search coil above the
ground. (see graph 19)
graph 19
Most valuable metals can produce reproducible signals. If the signal
cannot be repeated, it is mostly false. When a clear sound indicates the
buried target, you can read out the approximate category and depth of
the target on the LCD screen. You can also move above the target by
slowing down the probe to get a more repetitive signal.
5. Use the sound to help identify it
In the PARK mode, the sound discrimination system emits sounds at
three different frequencies to help with the discrimination.
Bass —— with iron-containing metal, 5
￠
nickel, etc.
Medium tone —— ring, soda bottle cap and zinc containing coins.
High-tone —— contains copper, aluminum, silver metals, such as 10
￠
,
25
￠
and other copper coins, silver coins.
6.
Use a digital cursor to help identify it
Refer to the following table as a preliminary guide.The table lists the
approximate numerical range of dollar and pound coins. During
