A multimeter is a measuring instrument with a capacity to measure current, resistance, and voltage all in one unit. In the market, you will find analogue and some of the best digital multimeters. While the analogue multimeters use a microammeter to display readings, digital multimeters represent the measured value through numeric and graphical bars.
Thanks to the precision and cost of digital multimeters, they are more popular than their analogue counterparts. As a matter of fact, many technicians prefer digital and only think about analogue when monitoring a measurement value that is rapidly varying.
Multimeters come in different constructions with those you can hold in the hand and others that are bench instruments specifically designed to measure high degree of accuracy. You can use these meters to troubleshoot a wide array of electrical problems on devices such as motor controls, electronic equipment, power supplies, domestic appliances, and wiring systems.
- 1 Digital Multimeters
- 2 Types of Digital Multimeters
- 3 What to Look for When Buying Digital Multimeters
- 4 The Best Digital Multimeter Reviews
As test tools, digital multimeters are standard diagnostic tools with a wide range of application in the electronic industry. They replaced analogue meters which were needle-based because of the greater impedance, reliability, and accuracy they brought into the measurement field.
The reason they are referred to as multimeters is because they combine the testing capabilities of single task meters such as ohmmeters, voltmeters, and ammeters. In addition, they have specialized features and options. Depending on your specific needs, you can go for the best digital multimeter that targets those particular tasks.
A typical digital multimeter has the following components:
- Display – This is the screen from which you take measurement read outs
- Buttons – These are used for selecting the many different functions. The arrangement and number of the buttons differs with model
- Dial – This is also known as the rotary switch and is used for selecting the primary measurement values which are ohms, amps, and volts.
- Input Jacks – These jacks are for inserting test leads. The test leads are wires plugged into the multimeter and serve as conductors between the item under testing and the multimeter.
The multimeters have different resolutions expressed as counts and digits. The advantage of knowing the resolution of a multimeter is to help you determine whether you can use it to detect a small change in the measured signal. For instance, a multimeter with a resolution of 1mV on a 4V range can help you see 1/1000th of a volt when reading one volt.
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Types of Digital Multimeters
There are 3 types of basic digital multimeters. Their differentiation is due to the functionalities they provide.
1. Fluke Digital Multimeter
If you want to calibrate the voltage usage and resistance of residential or industrial electrical, devices, this type of meter is recommended. It uses a large display screen that enables you to measure both voltage and resistance simultaneously.
Fluke multimeters are used commonly with car batteries and HVAC units. Electricians and anyone looking to measure critical components in electronics and electrical devices, this meter is very useful.
2. Clamp Digital Multimeter
This measures basic current flows in HVAC equipment, machines, and batteries. The meter comes with a clamp for attaching to the area of the device being measured. Using this meter, you can measure voltage, wattage, power consumption, and amps.
3. Autoranging Multimeter
With this multimeter, you can measure the readings you are gauging automatically. It comes with fewer settings and knobs and this leaves you with a handsfree device that does a lot of work behind the scenes.
Apart from the above categorization, digital multimeters can also be separated into 4 categories.
- Category 1 – This consists of multimeters purely used for testing electronic equipment and devices.
- Category 2 – In this group, you find digital multimeters designed for testing domestic appliances and loads.
- Category 3 – These are for industrial circuits. Here, you will find devices designed for small and medium sized industrial devices.
- Category 4 – Here, you will find digital multimeters for heavy duty testing. When looking for multimeters for residential feeds, electrical power lines, and main electrical components, Category 4 has all that and more.
What to Look for When Buying Digital Multimeters
When planning to purchase a digital multimeter, you need proper information so as to select a meter that is suitable for your needs and is a good value for money. The following are some of the considerations you should make.
This is the most crucial factor when buying any device let alone digital multimeters. All digital multimeters have an LCD display and therefore this should not be a consideration of whether to buy or not. Instead look at accuracy indications.
Determine what you want to measure as this will help you pick the best digital multimeter. For instance, if you are measuring ranges, a range selector with acoustic features can help you tell when you have a change in your setting.
Other features include resolution which refers to the fineness of the measurements your multimeter can capture. You can have resolutions in tenths and hundreds.
The price is dependent on resolution and features. On the lower end, you have cheap multimeters that are not calibrated which means in addition to the price you pay, you will have to incur another cost of calibrating. Calibration happens once per year on the minimum and for this you may have to pay from £40 upward.
You can get multimeters ranging between £45 and £400. If you decide to buy a cheap calibrated digital multimeter, you may end up replacing it as it becomes inaccurate over time.
Again, handheld multimeters tend to be cheaper than benchtop models. In many serious applications, benchtop models are considered the best digital multimeters.
Brands and Quality
This is another consideration that you have to make as different brands come at different prices and with varying functionalities. There are brands such as Megger, Extech, Draper, Martindale, and Kewtech which are considered reputable in the market.
With the above brands, you can be assured of quality and reliability in the measurement results. It can help looking at some reviews to determine what other people are saying concerning the specific models and brands.
The Best Digital Multimeter Reviews
1. AVO410 Megger Digital Multimeter
For testing with a high degree of accuracy, the Megger AVO410 is one of the best digital multimeter. It comes with a host of other features that makes it suitable for a wide array of usage and application. With this meter, you can do both AC and DC voltage and current flow measurements as well as resistance, capacitors, and frequency ranges.
- Autoranging – There is a range button that allows you to select multiple manual ranges on each function.
- Min Max Function – You can switch where necessary between minimum and maximum measurements using this function.
- Data Hold – This enables you to freeze a measurement result on the screen thus avoiding the need to remember it.
To add to the above functions, this multimeter is Cat IV 600V safety rated, has a digital display that is backlit and has 6000 counts.
2. Kewtech KT116 Multimeter
With this instrument, you can measure AC voltage, DC voltage, AC/DC current flows, continuity, resistance, frequency, capacitors, and temperature. It is portable and light in weight despite the loads of testing functions packed in it. It comes with a large rotary dial that allows you to select different modes.
- It measures AC/DC current flows all the way to 10 amperes and AC/DC voltage all the way to 600
- With the Min Max feature, you can test continuously.
- It comes with a continuity buzzer that is audible enough
- It has a sleep feature which can save you batteries
This multimeter complies with the safety standard IEC61010-1.
3. Draper 78997 Autoranging Digital Multimeter
This is an AC/DC meter whose rotary function has 13 positions. It also comes with a range selector, LCD screen, recessed terminals for safety purposes, and tough-molded plastic housing. You can use it for testing resistance, AC/DC current, AC/DC voltage, frequency, continuity, temperature, and diode test.
- It has a data hold feature which makes it easier to use because the measurements are frozen on the screen. This feature is unique to the best digital multimeter.
- Its 9 volts battery will serve you for a long time and it is not expensive to replace
- The display is illuminated and this gives you clear readings even in darker environments
It is advisable that you protect the equipment against debris and dust as these can clog it resulting into inaccurate readings.
4. Martindale MM39 Ranging Digital Multimeter
This digital multimeter is autoranging and has a range rotary switch that makes it simple to select the testing mode you want. It comes with two test buttons, one of which locks the range and the other freezes the results displayed on the screen.
- This equipment measures resistance to 20mΩ
- It measures AC/DC current flow to 10 amperes and AC/DC voltage to 600 volts
- Its safety rating is Cat III 600V
- With this equipment, you can also do continuity and diode tests
The continuity test is audible and the sound goes off at less than 25 ohms.
5. Extech MN15A Digital Multimeter
This is the master of convenience. It provides the utility of several measuring devices all in one casing. It can perform a total of 8 function which include AC/DC current measurement, AC/DC voltage measurement, continuity, resistance and diode testing. It can also perform thermocouple temperature measurements.
- Its display is large and backlit which makes it easier to take readings
- The housing is ergonomically designed to give you comfortable handling during operation
- The rotary function is large enough to allow you to switch between different settings
- The meter also complies with IEC61010-1 safety standard.
This is one of the best digital multimeter and can handle loads of household and professional applications including circuit breakers, automotive relays, outlets, junction boxes, and hardwired equipment.