G-Link
®
-LXRS
®
Wireless Accelerometer Node
User Manual
Sensor Settings and Operation
40
Figure 31 - Advanced Conversion Values Menu
Conversion Formula:
The conversion formula assumes a linear relationship between the
original units (such as A/D bits) and new engineering units (such as
g
-force ), and it is
expressed mathematically as
y=mx+b
, where
y
is the engineering units at a given point
(measurement),
m
is the slope of the line that represents the linear ratio,
x
is the original unit
value at a given point, and
b
is a unit conversion offset (in the case of unit conversions) or the
fixed zero load offset of the sensor (in the case of measurement calibration coefficients).
Negative values may be entered for any coefficient.
Slope:
is the linear scaling slope coefficient. The slope is the ratio of original units to new
engineering units (EU), and it is used to convert the sensor measurements. The slope
conversion value will vary depending on the engineering units desired. For example if the
original unit is A/D values (bits), and the desired engineering units are acceleration in g-
force, the slope conversion would describe how many bits equal one unit of
g
-force (bits/
g
).
Mathematically, the slope is
m
in the formula
y = mx +b
.
Offset:
is the linear scaling offset coefficient, and it is typically the starting output value of the
sensor with no load applied (in the original units). Mathematically, the offset is
b
in
y = mx +b
.
Effective Range:
the effective range is the calculated sensor measurement range in
engineering units (EU). The effective range is dependent on the slope, offset and resolution
of the node. The effective range is the number of bits per EU unit (slope) multiplied by the
total number of bits, minus the offset (if applicable).
