What are the parts of a multimeter?
What are the parts of a multimeter?
The main parts of a multimeter include the dial, test cables, sockets, display and buttons. Read our full guide to the parts of a multimeter!
Multimeter Dial
The dial on a multimeter is turned to set the instrument to the function you wish to carry out. It can also be how you turn the instrument on and off.
Some points on the dial can be double function, meaning that two or more of the settings will be found at a single point on the dial. In this case, it is sometimes necessary to push a shift button or similar (see below) to change between the functions.
Multimeter Test Cables
The cables supplied with a multimeter have a banana connector (DMM / 4mm connector). This is usually shrouded for extra safety when working with unsafe voltages.
There is a red and a black cable with each multimeter – the red represents the positive and the black is negative.
For multimeters with the capability to test temperature, a separate cable is provided, called a type K temperature probe (also known as a thermocouple).
This can be plugged into the common and the voltage sockets via an adapter or straight into a specialised socket available on some multimeters. The probe end of the cable is a very small sensor.
Multimeter Sockets
These sockets are where the test cables plug into the multimeter, however, there are usually more than two sockets on a single device. This is because the positive (red) cable usually requires a different socket when measuring amps than when measuring voltage.
The voltage socket is used for most other applications, including resistance, frequency and capacitance. There can be more than one socket for amps of different levels or units. Sockets can also be called ports or jacks.
Multimeter Display
The display on a multimeter is LCD (led crystal display). It displays the values for all readings in numerical form and will also state the unit of measurement for additional clarity.
To aid the user, some DMM’s will also incorporate a bar chart on the display to give the user an analogue style of indication, which is easier to interpret.
Multimeter Buttons
There are usually several buttons on a multimeter. These can include a power button and a light button; which brightens the backlight on the screen for better visibility.
Other buttons may include hold, shift and range, for example.
Hold Button
The hold button allows you to keep the reading on the screen after you have removed the probes. This is beneficial when the screen is not easily visible because of lighting or awkward angles.
Shift Button
The shift button is used to change functions of other buttons – rather like on a computer keyboard. So if there is more than one function (in the form of symbols or words) next to a button or point on the dial, the shift button will allow you access to the secondary function with one press and the third function with two pushes etc. The button may alternatively be labelled ‘mode’.
Range Button
The range button, found on auto-ranging multimeters that automatically adjust the units of measurement, allows you to set the range manually. An example of this is amps (A) to milliamps (mA) to microamps (μA) and back to amps (A). This is particularly useful when taking measurements close to two ranges, or when taking a number of measurements that could be in either range.
Auto-ranging multimeters are advantageous if you are unsure of the levels you will be testing. For more information, see: Things to consider when using a multimeter!
Another thing worth noting is that some multimeters will have a sleep mode, meaning they will automatically turn off after a period of inactivity before the button is pushed or dial moved. To turn it back on, press the power button or move the dial.
