Guralp Systems CMG-DM24 - Manual (Page 73)

Operator's guide
The different coloured lines show the results of experiments which
measure the power spectral density over several frequency bands.
Together, the results show a flat noise level over the entire passband to
within experimental error.
MINUTE
Syntax: duration MINUTE
Sets for how long the next SINEWAVE or RANDOMCAL calibration signal
will be injected, or the period of the next SQUAREWAVE calibration
signal.
duration is the desired interval, expressed in minutes. If you now
issue a SINEWAVE or RANDOMCAL command, the calibration will last
duration minutes; if the next calibration command is SQUAREWAVE,
a positive step of duration minutes will be generated, followed by a
negative step of a further duration minutes.
If you do not issue MINUTE, calibration signals will default to 2
minutes.
Because of the way FORTH works, you can insert MINUTE commands
into SQUAREWAVE, SINEWAVE or RANDOMCAL commands, for example:
N/S 4 HZ 5 MINUTE SINEWAVE
E/W 10 MINUTE SQUAREWAVE
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