CHAPTER 4 ■ DIGITAL MULTIMETER
Dual Display
A dual display includes a small, second set of digits in a corner of the display so that other measurements
or calculations can be displayed at the same time as the ongoing value. This is almost a requirement for
maximum, minimum, and the other calculated features, since the ongoing value is otherwise not displayed.
Many meters have this feature.
Maximum
A maximum mode displays the maximum value measured. This is actually a nice feature to test that a part
isn’t ever exceeding a specified range. While the meter continuously measures, you can exercise the various
parts of a circuit, pausing every so often to view the maximum value read by the meter. This way you don’t
need to watch the display all the time. Many multimeters have this feature.
Minimum
A minimum mode displays the minimum value measured. See the Maximum feature, previously described.
Many multimeters have this feature.
Stand
Most meters have a foldout piece to prop the meter up at an angle on the desktop (see Figure 4-10). This
makes it easy to read the display while working on the robot.
Figure 4-10. Multimeter held at readable angle by built-in stand
Optional Features
Here are some bonus features that are available on some multimeters, but not absolutely necessary to have:
Inductance
Measured in henries, inductance indicates the amount of opposition to changes in electrical flow. Very few
multimeters have this feature; otherwise, it would have made the nice-to-have list.