A digital multimeter (DMM) is a device utilised by specialists in the electric business to measure different values such as current, resistance, and voltage.
These units superseded the needle-based simple meters and have been around for quite a long time now.
The DMMs of today are more dependable and have more impedance than their analogue counterparts could ever muster.
The digital multimeters currently on the market consolidate various testing features in one unit.
If you have never worked with a Digital multimeter before, then you will be amazed at the convenience of having so many different options in the palm of your hand.
Most of the mid to upper range multimeters can test both AC and DC voltage and current at surprisingly high levels If you wish to measure unusually large currents, then you can always bypass the fuse by plugging the red lead into the auxiliary port.
DMN's typically include some advanced features for technicians who require specific functions. Read our guide on advanced multimeter functions for more details.
Let's get back to the basics:
A standard digital meter consists of four components
- an LCD to view measured values
- buttons which perform various operations
- a rotary switch which you use to select the appropriate measurement values (ohms, volts or amps, AC or DC)
- input jacks for the test leads.
You also receive two leads with your multimeter, a red and black for positive and negative poles.
These leads are made up of insulated wires that plug into the unit and two test probes at the end of each lead.
You may have heard the term “resolution” used for LEDs and LCDs, but for electrical testing devices, this means something completely different.
In multimeters, the resolution is not the number of pixels on a screen, but rather it describes the sensitivity of a particular device.
By knowing a meter’s resolution, a technician can determine whether it’s possible to detect a small change in the signal. For example, if a multimeter has a resolution of 10mV on its 300V range, it means you’ll be able to detect a change of 10mV on a measured voltage. This means that you can measure voltage in 300 000 steps!
Another way of putting it is the resolution of a multimeter refers to its sensitivity.
Modern DMMs had advanced and evolved significantly with regards to sensitivity and precision since Fluke introduced the first digital multimeter in 1977. As the demand for accuracy grew, it made much more sense to use a digital meter instead of an analogue one.
Modern digital multimeters are extremely versatile, and they come in a variety of shapes and sizes. Below we list the main categories for digital multimeters:
General purpose (aka Testers)
Here, at Santa's Reviews, we favour auto-ranging digital multimeters. This means The auto-ranging feature saves a lot of time and hassle because you don’t have to know the actual range yourself; the unit does that for you.
It also still allows you to set the range manually if you wish to do that.
A final note on safety
Whenever you perform a task with your digital multimeter, it will present potential safety hazards.
After all, you are measuring live current.
Before using any electrical test equipment, you should always first refer to the user’s manual for proper operating procedures, safety precautions, and limits.
So join us in celebrating the era of the digital multimeter, and let's help you choose the best DMM for your individual needs.