Chapter 9
Transfer Function and Noise Floor
Trillium Compact User Guide
16889R5
2014-03-04
48
The calibration sensitivity is not trimmed with the same accuracy as the ground motion
sensitivity. The calibration input can be used to verify the frequency response but not the
absolute sensitivity. The calibration input sensitivity, combined calibration sensitivity, and
input resistance of the available models of Trillium Compact are listed in
.
The units of the combined calibration response are rad/s because the calibration input
produces an equivalent acceleration, while the sensor passband is flat to velocity.
Therefore for a sinusoidal calibration you must divide the sensitivity listed by 2
π
f, where
f
is
the frequency of the sinusoid, to determine the expected gain at that frequency.
Table 9-3
Calibration circuit parameters for 120 s and 20 s models
Model
Calibration input
sensitivity at 1 Hz
Combined calibration
sensitivity at 1 Hz
Calibration input
resistance
120 s
0.011 m/(s
2
·V) ±7%
8.3 rad/s ±7%
120 k
Ω
20 s
0.010 m/(s
2
·V) ±7%
7.5 rad/s ±7%
133 k
Ω
