Hioki 3290-10, Instruction Manual

Page: 58 / 152

52
4.3 Measuring Current
Mode Selection
1.
Press the button to select the mode.
Button presses are ignored if TIME is displayed: press
→
to clear it.
For Current Measurement
For Frequency Measurement
DC Mode
Select this to measure DC current.
AC Mode
Select this to measure AC current.
AC+DC Mode
Select this to measure current other than the above. Examples
are shown below: waveforms with both AC and DC components,
and half- and full-wave rectified waveforms.
Hz
Hz Mode
Select this to measure frequency (in AC Mode)
Waveforms with both
AC and DC components
Half-wave rectified
waveform
Full-wave rectified
waveform
• In the DC mode, a low-pass filter
*
of about 0.5 Hz is applied to
suppress 50/60 Hz AC mains current ripple. This filter sup-
presses AC components leaving only the DC component for
display. However, this filter also slows measurement response,
so rapid current variations are not detected.
* Low-pass filter (LPF): a filter that passes only low frequencies
❖
See Section 5.4 "Filter Function" (page 95)
• In the AC mode, any DC component is removed. However,
when AC and DC components are both present and waveform
peaks exceed 2.5 times the range (crest factor), the waveform
is clipped by internal circuitry, and correct measurements are
not possible unless a higher range is selected.
❖
See "Range Selection" (page 53)
• To measure both AC and DC together, we recommend rms
measurement with the AC+DC Mode. However, to measure
only the DC component, use the DC Mode.
• When measuring current at 10 Hz or less, select AC+DC mode
and set the display update rate (measurement response time)
to SLOW. The SLOW display update rate is slower with the AC
mode selected than it is with the AC+DC mode selected.
• Frequency measurement uses AUTO ranging, so no current
range setting is needed.