YOKOGAWA WT200 User Manual page 42

4.4 Selecting the Measurement Range in case of Direct Input
Explanation
4-6
Manual Range (fixed) versus Automatic Range (auto)
The measurement range can be of one of the following types. The initial setting is
Auto range ON.
• Manual range
Voltage range: Select from 600 V, 300 V, 150 V, 60 V, 30 V, and 15 V.
Current range: Select from 20 A, 10 A, 5 A, 2 A, 1 A, 0.5 A, 200 mA, 100 mA, 50
mA, 20 mA, 10 mA, and 5 mA.
• Auto range: Auto
The measuring range is adjusted automatically according to the input voltage or
current as follows. Overrange is handled the same way as for the manually
selected range.
Range up:
A higher range is selected immediately if the instantaneous input voltage or
current exceeds approx. 300% of the rated value during sampling. If the
meaured voltage or current exceeds 110% of the rated value, a higher range will
be selected at the end of the current measurement cycle.
Range down:
A lower range is selected if the measured voltage or current drops below 30% of
the rated value. However, even when the measured voltage or current drops
below 30% of the rated value, range down will not be done when this would
result in waveforms with a high crest factor causing peak over.
Verifying the Range
To verify the current range setting press the V RANGE key or the A RANGE key. The
result will be shown at display C. In order to return to the measurement status, press
the same key again.
Note
When the range is set to auto, you cannot move to the minimum range by pressing the ∧ key.
•
On the other hand, when the range is set to the minimum, you cannot move to auto range by
pressing the ∨ key.
• When the range is set to auto, the range may be adjusted frequently if a waveform such as a
pulse is input. In such a case, set the range manually.
IM 253421-01E