Instantel Blastmate III, Руководство оператора

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Reference
BlastMate III Operator Manual
5–5
a. Geophone Operation
Functionally a geophone sensor is a coil of wire suspended around a magnet. The magnet is free
to move in a field of magnetic flux lines. By Lenzs' Law, induced voltage is proportional to the
speed at which flux lines are traversed. Induced coil voltage is therefore proportional to the
relative velocity of the coil to the magnet. In practice, it does not matter whether the coil or the
magnet moves. Only the motion and speed relative to each other are important.
Figure 5.5 Geophone Sensor Operation.
Geophone sensor specifications give a number known as the Intrinsic Voltage Sensitivity. It is the
coil voltage induced for a given coil versus magnet speed with units of V/in/s. In seismic
applications, the magnet is moved by the blast energy because it is coupled to the particles of the
surrounding terrain. The coil, because of its inertia, does not move and the resulting magnet
versus coil motion induces a voltage which is proportional to particle velocity.
b. Instantel Standard Transducer
Instantel offers a 2 to 300 Hz standard transducer in a round package. The transducer may be
installed on a floor, wall, or ceiling using a variety of installation procedures including ground
spikes, burying, mounting rod, or optional leveling plate with leveling feet and integrated bubble
level. The figure below includes an Instantel Standard Transducer (a) and a Standard Transducer
with leveling plate (b).