Minelab F3 Operation Manual page 21

Low Battery
Equipment Fault
Coil Fault
Noise Cancel
Circuitry within the F3 ensures that its performance remains
consistent as the charge state of the batteries begins to reduce.
When the batteries can no longer supply the necessary power to
sustain correct performance of the detector, a Low Battery Alarm will
alert the operator.
When Low Battery Alarm occurs the operator must
immediately STOP demining operations. The F3 should be
switched off and new or recharged batteries inserted into
the Battery Pack (Refer to Section 2.3.e for instruction on
Indicates batteries do
not have enough
charge to continue
detection
Indicates failure of
detector component or
a dislodged Red
Sensitivity Endcap
Indicates coil not
connected or not
receiving sufficient
current
Indicates Noise Cancel
procedure is occurring
NOTE
**WARNING**
changing batteries).
20
depending on target
metal composition and
depth
High pitched fast
continuous oscillating
tone
Low pitched slow
oscillating tone (ee-
aww, ee-aww)
Low pitched double
tone every five
seconds
Two single beeps
followed by 45 seconds
of short double beeps
finishing with four
single beeps