MEMS Tilt Beam Instruction Manual
RST Instruments
9
4 Analyzing the Data
Each MEMS Tilt Beam is identified by a Serial Number, and has a corresponding
Calibration Certificate (See Sample Calibration Certificate). To convert the sensor
signal into meaningful data, simply substitute the values from the readings and the
Calibration Constants into the following formula:
Sin
=
m(V-b)
Where
V
is the Tiltmeter Output signal.
m
is the predetermined Calibration Constant.
b
is the predetermined Calibration Constant.
The sensing principle of the MEMS Tilt Beam is that of an accelerometer with the
sensitive axis is oriented horizontally. The measured phenomenon is then the
component of gravity transverse to the sensitive axis, i.e.
a = g sine(
)
Commonly, MEMS Tilt Beam data are interpreted as linear motion
– i.e. rotation about
a presumed radius gives an equivalent motion. In many cases, where the ultimate
variable of interest is lateral displacement at some presumed radius due to rotation,
the accelerometer result can be simply rescaled, i.e.
x = r sine(
)
r a
= -----
g
In the case of a uniaxial MEMS Tilt Beam, radius (r) is the beam length. For MEMS Tilt
Beam on rigid bodies, the radius must be chosen with some care.
