Chapter 2 Working with DaqLab
75
Delta Y
)
0
(
1
1
=
−
=
t
G
G
y
Draws a line of the difference between the Y-coordinate of every point and Y-
coordinate of the first point. Use this function to move the data set along the Y-axis
so that the point will intersect the Y- axis at the origin.
Derivative
rate
sampling
t
t
y
y
y
n
n
n
1
,
2
1
1
=
Δ
Δ
−
=
−
+
Draws a line of the slopes of every three consecutive points of a data set. For high
recording rates and small
Δ
t, this line may be very noisy, which is why smoothing the
data set is recommended before applying the derivative function.
Divide
2
2
1
1
G
C
G
C
y
=
Draws a line of the division of two data sets
Envelope
(lower)
Lower envelope of G
1
with tolerance of C
1
points
Draws a line that connects the minimum values of a data set. The tolerance defines
the minimum distance (in sampling points) between two minima, so that the envelope
function is able to ignore random
noises
.
Envelope
(upper)
Upper envelope of G
1
with tolerance of C
1
points
Draws a line that connects the maximum values of a data set. The tolerance defines
the minimum distance (in sampling points) between two maxima, so that the
envelope function will be able to ignore random
noises
.
www.esis.com.au
Ph 02 9481 7420
Fax 02 9481 7267
