Manual

Publication GMSI10-UM013D-EN-P - May 2010
Configuration Parameters 59
Eng. Units Defines the native units of the transducer. Your
choice controls the list of possible selections
available in the Output Data Units parameter. It
also affects other module parameters.
Important: The XM-122 can produce gSE
measurements only with an accelerometer. The gSE
measurements are only available for the channel
when Eng. Units is set to "g."
Fault Low The minimum, or most negative, expected DC bias
voltage from the transducer.
Volts
Note: A voltage reading outside this
range constitutes a transducer fault.
Fault High The maximum expected DC bias voltage from the
transducer.
DC Bias Time Constant The time constant used for exponential averaging
(low pass filtering) of the transducer DC bias
measurement. The corner frequency for the low pass
filter is 1 / (2
π x DC Bias Time Constant). The
greater the value entered, the longer the settling
time of the measured value to a change in the input
signal. See example table below.
Seconds
Transducer Parameters
Parameter Name Description Values/Comments
Eng. Units
Options
Quantity of
Measure
g (gravity) Acceleration
ips (inch per
second)
mm/s
(millimeters per
second)
Velocity
mils (1/1000
inch)
um (micro
meter)
Displacement
Volts Voltage
Pa (pascals)
psi (pound-force
per square inch)
pressure
Time Constant
(seconds)
-3dB Frequency
(Hz)
Settling Time
(seconds)
1 0.159 2.2
2 0.080 4.4
3 0.053 6.6
4 0.040 8.8
50.03211
6 0.027 13.2
7 0.023 15.4
8 0.020 17.6
9 0.018 19.8
10 0.016 22