CMG-3V
This graph shows the entire process of unlocking and centring a triaxial
instrument:
1 – 5. The masses are checked, as described above, and unlocked, each in
turn.
6. The
BUSY
LED pulses to indicate that it is centring the
Z
component. The mass position output does not change for a
while, as it is beyond the range of the output. However, afer a
few pulses, the position of the
Z
component comes within range
and is centred. The pulses become more brief as this goes on, until
a pulse is missed (signifying that no corrective impulse is
needed.)
7. The
N/S
and
E/W
components follow in the same way, until all
three masses are centred and the process completes. The frst
round of centring has to move the
N/S
and
E/W
components all
the way from their end stops, whilst the
Z
component is ofen
closer to the proper position. Because of this, the frst
Z
centring
operation takes much less time than the others, and you may not
notice it.
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