Multimeter: The digital measuring device is so versatile
A multimeter is part of the standard equipment of every professional electrician, but the handy measuring device can also bring enormous added value regarding IoT projects or repairs in the private sector. It is versatile, easy to use and generally affordable. We tell you what exactly is meant by a multimeter, which variants there are and what you should bear in mind when using it.
What is a multimeter used for?
In many electrical engineering projects, it is necessary to measure the voltage and current of the respective device. In the past, separate measuring devices were needed for each of the individual measuring processes until a universal solution was developed in the form of the multimeter. This functions as a measuring device for several electrical quantities and is thus a particularly practical and flexible tool. It serves not only as an ammeter, but also as a voltmeter - and, incidentally, impresses with its very high measuring accuracy. You can also use a multimeter to measure the condition and properties of batteries and rechargeable batteries. However, the range of functions often goes far beyond this: many models are even able to measure electrical resistance, capacity, frequency, temperature, or other physical values. In addition, many multimeters are suitable for continuity and diode testing. A multimeter is no longer only used to measure current.
What should I bear in mind when using the device?
Regardless of whether your multimeter is used as a voltmeter, ammeter or for another purpose: the use of the respective device is basically very simple and therefore does not require any in-depth knowledge. Using a rotary switch, you can determine in a matter of seconds whether the multimeter should measure resistance, current, voltage or another electrical quantity. If you want to check the latter, it does not matter whether you want to measure direct current or alternating current and their respective voltages - the device proves to be a reliable voltmeter in both cases. Information on the technical functions of an ammeter and voltmeter can also be obtained from the circuit symbols on the device. Important: Before you start measuring, you should determine which electrical quantity is to be measured by turning the rotary knob. If you have already started measuring and the wrong electrical value was set, the device to be measured may be damaged. Most multimeters available today are used in a similar way. The devices are usually equipped with two connection sockets that have a different colour (usually red and black). You plug the matching-coloured test lead into each of the two sockets. At the other end of this lead are test probes that must be applied to the area to be measured. However, there are some important differences regarding the exact application - depending on whether you want your multimeter to function as an electric ammeter, voltmeter or resistance meter. You should therefore always refer to the enclosed instructions for use for precise information on the measuring procedure. The measuring leads mentioned are usually part of the scope of delivery. By the way: In addition to this classic version with socket and cables, there are also various other versions, such as voltage testers in pen format, USB multimeters or ammeters.
What types of multimeters are there?
There are different types of multimeters designed for different applications and measurements. Here are some of the most common types of multimeters:
A traditional multimeter that has a pointer and a scale. It can measure direct current, alternating current, resistance and other electrical quantities.
Digital multimeter (DMM):
A modern multimeter that has digital displays and functions. It can measure direct current, alternating current, resistance, capacitance, frequency, and other electrical quantities.
Clamp multimeter / current clamp:
A multimeter that measures the current through a wire or cable without interruption by placing a clamp around the cable.
Handheld multimeter / Handheld multimeter:
A portable multimeter designed for use on site or in the field. It can make a variety of electrical measurements and is usually rugged and resistant to shock and dust.
Benchtop Multimeter / Benchtop Multimeter:
A multimeter designed for use in the laboratory or workshop. It usually has advanced features and is larger than a handheld multimeter.
True RMS multimeter:
A multimeter that measures the rms value of alternating current or alternating voltage. It can make more accurate measurements of complex signals than a multimeter that only displays the peak value.
Automatic multimeter (DMM):
A multimeter that automatically selects ranges and takes the measurement without requiring the user to manually set the range.
Wireless multimeter: A multimeter that can send data wirelessly to a smartphone or computer. It is ideal for applications where measurements need to be taken in hard-to-reach places.
True RMS (Root Mean Square) is a measurement method used in multimeters to measure electrical signals. Unlike other methods that display the measured voltage or current as a peak or average value, True RMS measures the effective (RMS) voltage or current.
The effective voltage or current is the root mean square (RMS) of the amplitude over a period. This measurement method is particularly useful for complex signals such as sinusoidal waves or non-sinusoidal waveforms such as square, triangular, or sawtooth waves.
Multimeters with True RMS function can measure more accurately because they consider the total energy transmitted by the signal, regardless of the waveform. It is important to note that multimeters without True RMS function may give inaccurate readings for non-sinusoidal signals, as they display the peak or average value, which does not necessarily reflect the true energy of the signal.
This is what you should consider when buying
Before you buy a device, you should always read the product description carefully so that you know whether the multimeter in question can "only" measure current and voltage or whether it can also measure other electrical values. Only then can you be sure that the product is suitable for its intended purpose. Another decisive indicator is the CAT measurement category. This tells you what type of electrical device the measuring device can be used for.
There are four main categories, ranging from CAT I to CAT IV, with CAT I being the lowest category and CAT IV being the highest. The category depends on the type of electrical application in which the multimeter is used, and the type of voltage or current source being measured.
CAT I: Category I is used for measurements on electronic circuits and low-voltage devices, such as batteries or small electric motors.
CAT II: Category II is used for measurements on household appliances and other higher voltage equipment, such as electrical outlets and wiring in buildings.
CAT III: Category III is used for measurements on outdoor electrical equipment or equipment connected to a main distribution board.
CAT IV: Category IV is used for measurements on the main power supply, including measuring current and voltage at the terminals of the power supply.
It is important to choose the right CAT multimeter for the application to ensure that the multimeter will function correctly and minimise the risk of electric shock or other hazards.
Whereas the CAT multimeter was used in the past, nowadays almost only digital multimeters are available. At Berrybase, too, you will only find modern devices with digital displays. The advantage of these models is that the measured values are particularly easy to read. These are displayed on a modern LCD screen. In addition, all modern multimeters come in a practical pocket format.
Buy multimeters online: At Berrybase you will find top products at a low price
If you want to buy a multimeter for your upcoming IoT projects, Berrybase is the right place for you. Our range includes various high-quality measuring devices from renowned manufacturers such as UNI-T, McPower and PCWork. In addition to classic multimeters, you will also find other useful measuring modules in our shop, such as classic voltmeters and socket testers. Many models are already available for less than 30 euros and are therefore affordable even for tinkerers with a smaller budget. If you have any questions, our competent service team will be happy to help.