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The M-Scan finds ferromagnetic objects by sensing
the magnetic field radiated by the object. The locator contains
two sensor coil assemblies that are spaced apart and their
outputs electronically finely balanced. This is done so that the
M-Scan can correct for the ever-present magnetic field on the
earth. The two sensors measure the same field due to the earth
because both the coils are relatively close so they experience
the same magnetic lines of force. The earth’s magnetic lines
of force can be regarded as generally parallel but when
a ferromagnetic object is nearby the field strength and direction
of the magnetic lines upon each sensor is slightly different.
This is enough to disturb the critical balance allowing
the M-Scan to produce a different signal.
When no ferromagnetic objects are present, the speaker emits
a steady low frequency tone but as the M-Scan gets closer
to a ferromagnetic object the audio pitch increases until
the strongest signal from the object is directly under the end
of the sensor tube. The pitch is maximum over the strongest
signal and then decreases as the M-Scan is moved away.
(For a more detailed description of the way the field
of an object affects the M-Scan please refer to
the Application Notes in this manual.
How the M-SCAN Works
Summary of Contents for M-SCAN
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