4-8
IM DL350-01EN
Input Coupling (Coupling)
It is easier to measure the amplitude of an AC signal if you remove its DC component. On the other hand, there
are times when you want to measure the ground level or observe the entire signal, including both the DC and AC
components. In these kinds of situations, you can change the input coupling setting. By changing the setting, you
can choose how the vertical (voltage) control circuit is coupled to the input signal. You can set the input coupling
to one of the options listed below.
DC
The input signal is coupled directly to the attenuator of the vertical control circuit. Set the input coupling to DC
when you want to measure the entire signal, including both the DC and AC components.
AC (Only when measuring AC voltage)
The input signal is coupled to the attenuator of the vertical control circuit through a capacitor. Set the input
coupling to AC when you want to measure only the amplitude of the AC signal without the DC component.
GND
The input signal is coupled to the ground rather than to the attenuator of the vertical control circuit. Set the input
coupling to GND to check the ground level on the screen.
Vertical
control
circuit
Input terminal
1 M
Ω
Vertical
control
circuit
Input terminal
1 M
Ω
Vertical
control
circuit
Input terminal
DC
AC
GND
TC (Only when measuring temperature)
Set the coupling to TC when you are measuring temperature using the 701261 (UNIVERSAL), 701262
(UNIVERSAL (AAF)), 701265 (TEMP/HPV), 720266 (TEMP/HPV), or 720221 (16CH TEMP/VOLT).
DC-RMS
With the 720268 (HV (with AAF, RMS)), the DC and AC components of the input signal are converted to RMS
values and displayed. An RMS conversion circuit is connected to the same vertical-control-circuit coupling
arrangement that is used when the input coupling is set to DC.
AC-RMS
With the 720268 (HV (with AAF, RMS)), the AC components of the input signal are converted to RMS values and
displayed without the DC component. An RMS conversion circuit is connected to the same vertical-control-circuit
coupling arrangement that is used when the input coupling is set to AC.
Vertical
control
circuit
Input terminal
DC-RMS
RMS
conversion
circuit
AD
Vertical
control
circuit
Input terminal
AC-RMS
RMS
conversion
circuit
AD
1.8 M
Ω
200 k
Ω
1.8 M
Ω
200 k
Ω
ACCEL (Only when measuring acceleration)
To measure acceleration with the 701275 (ACCL/VOLT), set the input coupling to ACCEL.
OFF (For the 16-CH Voltage Input Module and 16-CH Temperature/Voltage Input Module)
Set the coupling to OFF to not include in the measurement the sub channels selected on the 720220 (16CH
VOLT) or 720221 (16CH TEMP/VOLT).
4 Vertical Axis