Guralp Systems CMG-3T - Manual (Page 29)

Operator's guide
3. Repeat this measurement for several tilt angles.
4. For the vertical sensor, the input acceleration is given by
a = g sin φ, whilst for the horizontal sensor, it is
a = g ( 1 – cos φ ).
Calculate the input acceleration for each of the tilt angles used,
and plot a graph of mass position output against input
acceleration.
5. The gradient of the line obtained gives the sensitivity of the coil
(in V/m/s², if g was measured in m/s² and the mass position in
V.)
6. The coil constant K is equal to this sensitivity divided by the
value of the displacement feedback resistor, as given on the
calibration sheet.
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