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GSM19 Series Magnetometers - Version 7
GEM Systems, Inc. Advanced Magnetometers
For more technical information, visit www.gemsys.ca
The definition of cycle time is different for different survey modes:
•
In mobile, gradiometer, vlf or gradi vlf modes, the GSM-19 does not cycle
automatically. You must press a button to take each reading.
The cycle time in these modes represents the maximum waiting time to match the seconds and
fraction of seconds to those of a base station unit cycling at the same rate. This ensures that
there is a reading on the base station taken precisely at the same time, and that interpolation of
the base unit readings is not required during diurnal corrections (see section 5.9).
When the unit is set to
immediate start
, lines 6 & 7 of the LCD show
immediate start
(correction with interpolation)
. This means that once in survey mode, pressing any button
starts a reading immediately. Because there is no waiting time, the time stamps of the readings
of the mobile unit may not match the time stamps of the readings of the base station. During
diurnal correction the base readings are linearly interpolated to the time of the mobile unit.
•
Base, walk, fast and marine modes are auto cycling modes. The cycle time is the time between
consecutive readings.
For more precise diurnal correction, press
D+
or
C-
to select the same cycle rate as the base unit.
NOTE:
To perform diurnal corrections, the time of the mobile and the base MUST also be
synchronized. See Time Synchronization in section 5.8.
5.3.8 Tuning the Magnetometer
In the
Survey Menu
, press
F
to highlight
tuning
.
SCREEN 21
survey mode position time file
cycle
time
tuning
AC filter
display mode text ID
initialize N auto-tune Y056
A-start C-change
←
BF
→