IM 253401-01E
4-1
4
Setting Measurement Conditions
4.1
Selecting the Measurement Mode
Relevant Keys
SCALING
AVG
FILTER
STORE
RECALL
HARMONICS
SAMPLE
V OVER
A OVER
MODE
RMS
V MEAN
DC
A
B
C
hour
hour
min
min
sec
V
VA
m
A
k
var
M W
TIME
V
PF
m
A
k
deg
M W
%
FUNCTION
AUTO
AUTO
MODE
1
Φ
3W
V
Hz
m
A
k
h
M W
TRIG
V RANGE A RANGE
HOLD
ENTER
INTEGRATOR
START
HARMONICS
MEMORY
INTEG SET
STOP
RESET
REMOTE
INTERFACE
OUTPUT
LOCAL
SETUP
h
SHIFT
WIRING
3
Φ
4W
3
Φ
3W
3V3A
ELEMENT
1
2
3
FUNCTION
ELEMENT
1
2
3
FUNCTION
ELEMENT
1
2
3
*Shows the operation panel of the WT130. For the differences
between WT110 and WT130, refer to section 2.2, page 2-2, 2-3
Displays
relevant
keys and
indicator
Operating Procedure
RMS
V MEAN
DC
MODE
V RANGE
SHIFT
MODE
V RANGE
SHIFT
MODE
V RANGE
SHIFT
Explanation
Measurement Mode
One of the following measurement modes can be selected for measurement of voltage and
current. The initial value is “RMS”.
Indicator
Voltage
Current
RMS
Measures and displays true
Measures and displays true RMS
RMS value
value
V MEAN
Displays rectified mean value
Measures and displays
calibrated to the RMS value
true RMS value
DC
Displays DC value obtained by
Displays DC value obtained by averaging the input
averaging the input signal
signal
Theoretical Equations
• RMS
This mode is selected to display input voltage or current as a true RMS value.
1
T
0
T
f (t)
2
dt
f (t) : input signal
T
: one period of the input signal
• V MEAN
This mode is selected to display input voltage or current as a rectified mean value calibrated
to the RMS value. Since a sine wave is used for calibration, the value displayed will be the
same as that obtained in RMS mode if a sine wave is measured. The value displayed will be
different from that obtained in RMS mode if a distorted or DC waveform is measured.
π
2 2
•
2
T
0
T
2
f
(t )
dt
f (t) : input signal
T
: one period of the input signal
• DC
This mode is selected when the input voltage or current is DC. The input signal is averaged
and the result is displayed.