Guralp Systems CMG-3ESPCD - Manual (Page 36)

CMG-3ESPCD Digital Broadband Seismometer Calibrating the 3ESPCD
set to the model number of your instrument and Instrument Response
should be set to correct code, as given in section 4.3.1 on page 37,
followed by eirther “v” or “velocity”.
If the file calvals.txt exists in the same directory as Scream!'s
executable (scream.exe), Scream! will look there for suitable calibration
values. A sample calvals.txt is supplied with Scream!, which you
can edit to your requirements. Each stream has its own section in the
file, headed by the line [instrument­id]. The instrument­id is
the string which identifies the digitiser in the left-hand pane, e.g.
GURALP­DEMO. It is always 6 characters (the system identifier)
followed by a dash, then 4 characters (the serial number). For example:
[GURALP-DEMO]
Serial-Nos=T3X99
VPC=3.153,3.147,3.159
G=1010,1007,1002
COILCONST=0.02575,0.01778,0.01774
CALVPC=3.161
CALRES=51000
TYPE=sensor-type
RESPONSE=response-code
9. Click . The script will return with a graph showing the
responsivity of the sensor in terms of amplitude and phase plots for
each component.
The accuracy of the results depends on the amount of data you have
selected, and its sample rate. To obtain good-quality results at low
frequency, it will save computation time to use data collected at a lower
sample rate; although the same information is present in higher-rate
streams, they also include a large amount of high-frequency data which
may not be relevant to your purposes.
MAN-C3E-0002 36 Issue B - November 2013