Guralp Systems CMG-3T - Manual (Page 26)

CMG-3T
Most data can be found on the calibration sheet for your sensor.
Under Instrument response, you should fill in the sensor
response code for your sensor, according to the table below.
Instrument Type should be set to the model number of the
sensor.
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
[instrument-id]. The instrument-id is the string which
identifies the digitizer in the left-hand pane, e.g. GURALP-DEMO.
It is always 6 characters (the system identifier) followed by a
dash, then 4 characters (the serial number.) For example:
[instrument-id]
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 OK. The script will return with a graph showing the
responsivity of the sensor in terms of amplitude and phase plots
for each component (if appropriate.)
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
26 Issue N