Advanced features of a digital multimeter
From control circuits to small embedded computers, integrated circuits enable modern digital instruments to provide more functionality.
Common enhanced measurements include:
Measurement of semiconductor junction voltage drop that limits current, used to determine the type of transistor;
The graphical display of measurement quantities, such as bar charts;
Can make it easier to measure through (go/no go);
Continuously measure and sound an alarm when a circuit condition occurs;
Low frequency oscilloscope;
Telephone testing device;
Automatic circuit testing, including automatic timing, delay signals, etc;
Simple data detection functions, such as recording the maximum and minimum readings for a specified period, or obtaining a certain amount of sample readings at fixed intervals
Sampling and holding, the last reading can be locked for reading after the device is removed from the testing circuit;
Automatic conversion of test range, the instrument automatically selects the appropriate measurement range during measurement, protecting the instrument from damage.
Digital multimeters typically have circuits or software that can ensure accurate measurement of AC voltage at any frequency. This type of multimeter uses the root mean square method to combine input signals, so that even if the input signal is not an ideal sine wave, it can correctly read the true voltage value.
Some modern multimeters can be connected to personal computers through infrared, RS-232, or IEEE-488 device buses. Through these methods, computers can record readings during measurement or upload a set of results from the device to the computer.
Modern devices and systems are becoming increasingly complex, and multimeters are gradually becoming less common in technician toolboxes; More complex and specialized equipment is replacing it. For example, when measuring an antenna, the staff may have used an ohmmeter to measure its resistance; Modern technicians may use handheld analyzers to test several parameters in order to determine the integrity of antenna cables
