Hioki RM3545, Инструкция по эксплуатации, Страница: 76 / 364

4.3 Zero Adjustment
68
Perform zero-adjustment in the following circumstances:
•
When you wish to increase the measurement precision
→
For some ranges, there may be a component added to the accuracy if zero-adjust-
ment is not performed.
See: "Measurement Specifications" (p. 250)
•
The measured value is not cleared due to thermal EMF or other factors.
→
The measured value will be adjusted to zero. (*1)
•
Four-terminal connection (called Kelvin connection) is difficult.
→
The residual resistance of the two-terminal connection wires will be canceled.
*1 Accuracy specifications vary when zero-adjustment has not been performed.
For more information, see "Chapter 13 Specifications" (p.249).
Thermal EMF can also be canceled by using OVC. (p.82)
For more information about how to perform zero-adjustment properly, see "Appendix 6 Zero
Adjustment" (p. A7).
Before Zero Adjustment
•
Execute zero adjustment when the ambient temperature has changed, or when a mea-
surement lead is replaced after zero adjustment was performed. However, when perform-
ing zero-adjustment is difficult, for example when using the L2102 or L2103 Pin Type
Lead, perform zero-adjustment using the standard included L2101 Clip Type Lead or sim-
ilar lead and then switch to the pin type lead to perform measurement.
•
Zero adjustment should be executed in each range to be used. Perform zero-adjustment
for the current range only when setting the range manually or for all ranges when using
auto-ranging.
•
When zero adjustment is executed with auto-ranging, correct zero adjustment may not be
possible if the delay time is too short. In this case, execute zero adjustment with a manu-
ally set range.
See: "3.2 Selecting the Measurement Range" (p.49)
"4.9 Setting Pre-Measurement Delay" (p.84)
•
Zero adjustment values are retained internally even when the instrument is turned off.
They are also saved with panels. You can also elect not to load zero-adjustment values
from panels.
See: "6.1 Saving Measurement Conditions (Panel Save Function)" (p.120)
"6.2 Loading Measurement Conditions (Panel Load Function)" (p.121)
•
Zero-adjustment can be performed even when the EXT I/O 0ADJ signal is ON (when
shorted with the EXT I/O connector’s ISO_GND pin).
•
When switching the offset voltage correction (OVC) function, measurement current, or
low-power function, zero adjustment will be canceled automatically. If necessary, repeat
the zero adjustment process.
•
Although resistance of -1%f.s. to 50%f.s. can be canceled in each range, try to keep the
canceled resistance to 1%f.s. Zero-adjustment cannot be performed for 100 M
Ω
and
higher ranges.
4.3 Zero Adjustment
LP f.s.
OFF 1,000,000dgt.
ON 100,000dgt.