Hioki 3285-20, Instruction Manual, Page: 42 / 85

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2.2 Current Measurement
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NOTE
2.2.2 Measuring AC Current (AC A)
1. Press button to display .
2. Switch between the auto range and the manual range
as necessary.
3. Open the top ends of the clamp core and clamp the
measured conductor so that it passes through the
center of the clamp core.
Just after suspension of input, or when modes are
switched under no input, the counter would not
become zero for about 10 seconds. This is normal
and simply reflects the workings of the internal
circuit. But you can measure with guaranteed
accuracy before the counter becomes zero.
Depending on ambient temperatures, the counter
would not become zero under no input. If this
happens, perform a zero-cancel correction (See
3.1.2: Zero-Cancel Correction Function).
During a f.s. input, the measurement response speed
is about 250 ms during rise (0% to 90%) and about
500 ms (100% to 10%) during fall (See: Figs. 1 and
2).
The AC A mode does not allow measurement of DC
waveforms, full-wave rectification waveforms, half-
wave rectification waveforms, or DC+AC
waveforms (See 1.5: Modes).
The 200 A range will display up to 250 A, however,
only the range from 10 A to 200 A can be displayed
with guaranteed accuracy.
At any range, gross errors may occur at 1% or
below of the range ,whose accuracy is not
guaranteed, as a result of internal corrective
calculations.