Geometrics Memory-Mag G-856AX, Руководство по эксплуатации

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Geometrics, Inc
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G-856AX Operation Manual
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Figure 15. Attach the gradiometer switch box.
Base-station Assembly
The effects of the diurnal variation of the Earth’s magnetic field can be removed from
survey measurements if measurements were made during the survey with a base-station
magnetometer. This magnetometer operates in a fixed location while the survey
magnetometer is used to acquire magnetic field measurements over the survey area.
In order to provide a useful base-station reference, the base-station magnetometer sensor
should be positioned at least 1 m above the ground surface and well away from moving
magnetic objects or structures that will generate a strong magnetic gradient. The sensor
should also be mounted on a stable structure in order to minimize wind-induced motion
of the sensor. Geometrics provides a base-station kit that can be used with the G-856AX
staff sections to construct a stable base-station tripod.
The tripod kit includes a tripod base and two (2) leg tips. The tripod assembly is shown
in Figure 16 with sensor attached. Here, the bottom staff section and the two middle staff
sections have been inserted into the three inclined holes on the underside of the tripod
base. Leg tips have also be slipped on the ends of the two middle staff sections. Attach
the sensor to the top staff section before inserting this piece into the tripod base. The top
staff section is inserted into to central hole on the top of the tripod base so that it slides
past the internal O-ring and rests on the bottom of the hole. The O-ring will prevent the
sensor from rotating under the influence of the wind.