Hioki CHT3548, User Manual, Page: 36 / 81

Hope Electronics Technology Manual
Edition
V1.0 36
Chapter 4 Customizing Measurement Conditions
This chapter describes the functions useful to perform more sophisticated
and accurate measurement.
4.1 Using Zero Adjustment
In the following cases, perform zero adjustment:
(A resistance of up to ±3%f.s. can be canceled for any range.)
l The measurement value is not cleared due to thermal EMF or other factors.
Ø The measurement value will be changed to zero.
Accuracy is not affected by whether or not the zero adjustment is performed.
The thermal EMF can also be canceled by using OVC.
l Four-terminal connection (called Kelvin connection) is difficult.
Ø The residual resistance of the two-terminal connection wires will be canceled.
IMPORTANT
l
When the ambient temperature changes or the test leads are replaced
after zero adjustment, perform zero adjustment again.
l Perform zero adjustment for each range used. In the manual range
mode, only the current range is adjusted to zero. In the auto range
mode, all ranges are adjusted to zero.
l
Zero adjustment values are held internally even if the instrument is
power off, but they are not saved in the panel.
l When the offset voltage compensation (OVC) function is turned from
ON to OFF or from OFF to ON, the zero adjustment is cleared. Perform
zero adjustment again.
l
When the measurement current is changed from Lo to Hi or from Hi to
Lo, the zero adjustment is cleared. Perform zero adjustment again.
l When a lower resistance is measured after zero adjustment, the
measured value will be negative.
Example: 2mΩ is connected in the 300mΩ range and then zero adjustment
is performed.
If 1 mΩ is measured, -1 mΩ is displayed.