White Mini-Seis III Pro, Руководство по эксплуатации

Страница: 34 / 49

Mini-Seis III Pro™ Operating Manual Page 34
Field Use
It is strongly recommended that the user obtain a copy of the ISEE Field Practice Guidelines
for Blasting Seismographs (available from the ISEE at
www.isee.org ). Our recommendations
for field use follow these guidelines.
Transducer Coupling
Burial of the seismic transducer package is recommended, except in super-saturated soil
conditions. To bury the transducer first connect the spikes. Then dig a hole roughly six
inches deep. The bottom of the hole should be relatively flat and smooth. Orient the arrow
on top of the transducer toward the vibration source and press the transducer assembly into
the bottom of the hole. Carefully replace the soil around and over the transducer. After
monitoring, care should be used when removing the soil so that the transducer cord will not
be cut.
For surface spiking in good soil conditions, first connect the spikes. Orient the arrow on top
of the transducer toward the vibration source and press the transducer assembly firmly into
the earth. A sandbag may also be used.
When mounting on concrete is necessary, bolting or gluing of the transducer package is
recommended. Never simply place the transducer on concrete without proper coupling.
Note: Transducer coupling becomes a significant issue whenever
ground accelerations approach or exceed 0.2 gravities. At a
frequency of 30 hertz, a particle velocity of 0.40 ips (10 mmps)
yields 0.2 g acceleration.
Microphone
The microphone will normally be installed in the provided microphone stand. Another
method is to use tape to fasten the microphone to a rod driven into the ground. The
supplied wind screen should always be used to prevent the acoustic readings from being
influenced by wind. Also, use the supplied rain shield package to protect the microphone
from any rain. To use the rain shield package, put it over the microphone and loosely tie it
off at the bottom with a rubber band or similar item.
Note: Never use tape or any material that directly obstructs the
microphone element. The linear weighted microphone is used to
record changes in overpressure. The measurements will be
valid as long as the pressure around the element changes
uniformly with the pressure change in the environment.