Guralp Systems ART - Manual (Page 10)

ART
Sensor
Sensor type code
(response-type) Units
(V/A)
CMG-3TB or 3V / 3ESP borehole,
360 s – 50 Hz response
CMG­3B_360S_100HZ V
Some English descriptions are also accepted, e.g.
“120s velocity”, “100Hz acceleration”.
• To set the sensitivities (or gains) of the sensor
components, include the line
G=vertical­sens,N/S­sens,E/W­sens
These values are given on the sensor calibration sheet. For
velocity sensors, they are given in units of V m
–1 s (V/m/s).
The gain of an accelerometer is expressed in V m -1 s 2 (V/m/
s 2 ). Because Güralp Systems sensors and digitizers use
differential inputs and outputs, the sensitivity is quoted as
2 × (single-ended sensitivity) on the calibration sheet.
• To set the coil constants of the sensor components,
include the line
COILCONST=ZCC,NCC,ECC
Where ZCC is the vertical coil constant, NCC is the
North/South coil constant and ECC is the East/West cost
constant. These values are given on the sensor calibration
sheet.
• To set the local acceleration due to gravity, include the
line
GRAVITY=acceleration
You should give this value in m s –2 , if you know it. If you
miss out this line, Scream! will use a standard average
g value of 9.80665 m s
–2 .
2.2.1 Examples
The calibration information for a CMG-3T weak-motion velocity
sensor might look like the following:
[GURALP-CMG3]
Serial-Nos=T3X99
VPC=3.153,3.147,3.159
G=1010,1007,1002
10 Issue C