Hioki RM3545, Instruction Manual, Page: 57 / 364

3.2 Selecting the Measurement Range
49
3
The measurement range can be set as follows. Auto-ranging (the AUTO range) can also be
selected.
Manual Range Setting
Auto-Ranging
Switching from Autoranging back to Manual range selection
Press
again. The range can now be changed manually.
•
When the comparator function and BIN measurement function are turned on, the range
cannot be changed from fixed (it cannot be switched to auto-ranging). To change the
range, turn off the comparator function and BIN measurement function or change the
range from within the comparator settings and BIN number settings.
•
When measuring certain motor, transformer or coil components, the auto range setting
may not stabilize. In such cases, either specify the range manually or lengthen the delay
time.
See: "4.9 Setting Pre-Measurement Delay" (p.84)
•
The measurement target power is given by (resistance value × (measurement current)
2
)
if the measured value is within the measurement range. If the measurement range is
exceeded, the power may reach a maximum value that is given by (open voltage × mea-
surement current). Check the measurement range before connecting the measurement
target. When using a High measurement current, resistance ranges of 100
Ω
and lower
may cause a large amount of power to be applied to the measurement target. In particu-
lar, a maximum power of about 2 W may be applied to the target at ranges of 100 m
Ω
and
lower (ranges that result in a measurement current of 1 A). Check the measurement
range and current switching before connecting the measurement target.
See: "4.2 Switching Measurement Currents (100 m
Ω
to 100
Ω
)" (p.66)
•
When measuring delicate samples, use the Low Power measurement mode.
See: "4.1 Switching to Low-power Resistance Measurement" (p.64)
•
Refer to "Resistance Measurement Accuracy" (p. 250) for information on each range
measurement accuracy.
•
When using the INT trigger source, current will stop when a contact error occurs (when
not connected to the measurement target). By contrast, when using the INT trigger
source with the contact check function off, the measurement current is always applied,
even when the instrument is not connected to the measurement target. Consequently, a
rush current will flow at the moment the instrument is connected to the target (for
example, measuring a pure resistance in the 1 A measurement current range will result in
a maximum current of 5 A with a convergence time of 0.5 ms). When measuring easily
damaged elements, either turn on the contact check or use a range that results in a low
measurement current. However, if there is chatter even when the contact check is
enabled, it will not be possible to completely prevent a rush current.
•
When set to 2-wire with the multiplexer, ranges of 10
Ω
and lower cannot be used.
3.2 Selecting the Measurement Range
Select the range to use. (AUTO off)
The decimal point location and unit indicator change with each
key press.
Press this while a manual range is selected. (AUTO lights)
The optimum measurement range is automatically selected.