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→Digital Multimeter
===Controls===
===Controls===
The buttons you need to be most familiar with when using the digital multimeter are the function keys: DC V, AC V, Ω, Freq, AC+DC, and diode (that's what that symbol is). To access the functions written in blue, press the shift key and then press the respective function key. The blue functions include: DC I, AC I, Continuity, Period, dB, dBm. Let's talk about all of them very briefly.
The buttons you need to be most familiar with when using the digital multimeter are the function keys: DC V, AC V, Ω, Freq, AC+DC, and Diode (the symbol that looks like a triangle pointing at a vertical line with two horizontal leads sticking out the ends). To access the functions written in blue, press the shift key and then press the respective function key. The blue functions include: DC I, AC I, Continuity, Period, dB, dBm. Let's talk about all of them very briefly.
The DC V function will measure a DC voltage
The DC V function will measure a DC voltage (e.g. DC power supply). The AC V function will measure an AC voltage (e.g. function generator). The Ω function will measure real resistance (e.g. potentiometer). The Freq function will measure the frequency of an AC voltage signal from 5Hz through >1MHz. The AC+DC function will measure the True RMS value of AC+DC voltages or currents (i.e. AC signals with a DC offset). See the user manual for more info. The Diode function will measure the forward voltage drop of general-purpose diodes and Zener diodes.
For the functions in blue... The DC I function will measure DC current. Don't ask why the electrical engineers decided to use the variable "i" for current. It's complicated. The AC I function will measure AC current. Do not attempt to measure the AC current from a wall outlet; you will blow something up (potentially including yourself). The Continuity function (that looks like three sound waves) will deliver an audible beep when the probes sense less than 10Ω between them. The purpose of this function is to test the quality of various connection points in your circuit. It can answer questions like... Is this a good solder joint? Are these two components joined at the same node? Is this point in the circuit connected to ground? Did I accidentally fry this component? The Continuity function is an invaluable troubleshooting tool that allows you the freedom to poke around in your circuit to see if everything is connected like it's supposed to be. In most cases, you should have all source voltages turned off when you are testing continuity. The Period function will measure the time period of an AC voltage signal from 0.2s through <1μs.
===Plugging In The Leads===
===Plugging In The Leads===
It is very important that you plug in the leads (cables, banana jacks, whatever you want to call them) into the correct terminals to make your measurement. The correct input terminals can change depending on what type of measurement you are performing. Failure to choose the correct terminals and set up the measurement properly can result in a blown fuse, damage to the digital multimeter, damage to another benchtop instrument, and/or damage to your circuit. So... read what each terminal is meant for before you start plugging things in willy-nilly.
It is very important that you plug in the leads (cables, banana jacks, whatever you want to call them) into the correct terminals to make your measurement. The correct input terminals can change depending on what type of measurement you are performing. Failure to choose the correct terminals and set up the measurement properly can result in a blown fuse, damage to the digital multimeter, damage to another benchtop instrument, and/or damage to your circuit. So... read what each terminal is meant for before you start plugging things in willy-nilly.
==Common Ground==
==Common Ground==
Ground (sometimes called neutral or earth) is usually at 0V. Ground acts a reference point for most electronic circuits.
Ground (sometimes called neutral or earth) is usually at 0V. Ground acts a reference point for most electronic circuits.