Guralp Systems CMG-EDU - Manual (Page 36)

CMG-EDU
This command is in the extended dictionary; to use it, first issue the
command ok-1 and finish with [seal].
5.4 Calibration
5.4.1 SINEWAVE
Syntax: Z freq-or-period unit SINEWAVE
Instructs the CD24E1 to inject a sine-wave calibration signal, starting
on the zero crossing.
Z denotes the Z channel of the digitizer. This is used for the CMG-
EDU's single component (whether vertical or horizontal.)
freq-or-period and unit together determine the frequency of the
calibration signal. If unit is HZ, then freq-or-period is taken as a
frequency, in Hz; if SECOND, then it is interpreted as a period, in s. For
example:
Z 4 HZ SINEWAVE
freq-or-period must be an integer; if you want to specify a period
of, for example, 0.5 s, you should specify it as 2 HZ instead.
The calibration signal will be automatically disconnected after 2
minutes if you have not altered the setting using the MINUTE
command, described below.
Whilst the calibration signal is being generated, it is output on the
channel MB as well as being fed into the sensor. Calibration is done by
comparing the data from the MB channel with the sensor's normal data
stream.
Note that the MB channel is a 16-bit channel whilst the signal is
digitized at 24 bit resolution. If using Scream! to measure signal
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