Chapter 3: DX Series
32
DX-VBR
DX-VBR contains one vibration sensor and a pair of terminals for
connecting a contact closure (CC) sensor.
Vibration sensor:
The built-in vibration sensor detects the vibration of any object where
DX-VBR is affixed. The sensor determines the vibration by measuring the
accelerations in three mutually perpendicular directions, and then
generating a numeric value representing the magnitude of the
acceleration due to gravity of the Earth. Below is the calculation formula.
a = (a
x
2
+ a
y
2
+ a
z
2
)
1/2
The acceleration has two measurement units:
g
and
milli-g
.
1 g = 9.80665 m/s
2
1 milli-g = 0.001 g
"a" in the above formula denotes the magnitude of the acceleration.
0 <= a <= 3.464 g
Note: <= means "less than" or "equal to."
a
x
, a
y
and a
z
represent the accelerations in three mutually
perpendicular directions x, y and z.
x, y and z form a Cartesian coordinate system.
-2 g <= a
x
<= 2 g
-2 g <= a
y
<= 2 g
-2 g <= a
z
<= 2 g
