YOKOGAWA WT210, User Manual, Page: 86 / 316

4-18
IM 760401-01E
Setting Averaging ON/OFF
ENTER
3.
4.
( Display C )
ENTER
5.
End of setting
Set the averaging function
( Display C )
SETUP
1.
2.
Explanation
About the Averaging Function
This function performs exponential averaging or moving averaging on measurement
values. When the displayed values are unsteady due to big fluctuations in power
source or load, or due to the low frequency of the input signal, this function is useful to
stabilize the displayed values for easier reading. The measurement items that are
averaged directly are V (voltage), A (current), and W (active power). When using
those measured V, A, and W values to calculate other measurement items, those
items receive the effects of the averaging. Since certain values would lose their
meaning if they were averaged (such as the peak (Vpk, Apk) values), averaging is not
performed on them.
Selecting the Type of Averaging
The following two selections are available. The initial value is “Lin”.
• Exponential Averaging: EP
Exponential averaging is expressed by the following equation.
D = D
n–1
+ (M
n
– D
n–1
)/K
where
D
n
: the value at the n
th
display;
D
n–1
: the exponentially averaged value at the n-1
th
display;
M
n
: the measurement value at the n
th
display;
K: attenuation constant
• Moving Averaging: Lin
Moving averaging is expressed by the following equation.
D
n
= (M
n–(m–1)
+ M
n–(m–2)
+ ... M
n–2
+ M
n–1
+ M
n
)/m
where
D
n
: the value at the n
th
display;
M
n–(m–1)
: the measurement value at (m–1) display before the n
th
display;
M
n-(m–2)
: the measurement value at (m–2) display before the n
th
display;
:
M
n–2
: the measurement value at two displays before the n
th
display;
M
n–1
: the measurement value at one display before the n
th
display;
M
n
: the measurement value at the n
th
display;
m: sample number
4.7 Using the Averaging Function