3Multimeter Features
Making Relative Measurements (Null)
68 U1231A/U1232A/U1233A User’s Guide
Making Relative Measurements (Null)
When making Null measurements, also called relative, each
reading is the difference between a stored (measured) null
value and the input signal.
One possible application is to increase the accuracy of a
resistance measurement by nulling the test lead resistance.
Nulling the leads is also particularly important prior to
making capacitance measurements.
1 To activate the relative mode, press the key. The
measurement value at the time, when Null ( ) is
enabled, is stored as the reference value.
Figure 3-2 Null display
2 Press again to view the stored reference value. The
display will return to normal after 3 seconds.
3 To disable the Null function, press while the stored
reference value is shown (step 2).
For any measurement function, you can directly measure and
store the null value by pressing with the test leads
open (nulls the test lead capacitance), shorted (nulls the test
lead resistance), or across a desired null value circuit.
Null can be set for both auto and manual range settings, but not in the
case of an overload.