Multimeters

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Multimeters

Multimeter.jpg
Synonyms: multitesters;
DE: Vielfachmessgeräte
Type: measuring tool
Material: circuits, electronic components
Tutors: Patrick

Multimeters are an essential tool for working with electronics. They are used – as the name suggests – to measure various values of a circuit like:

  • voltage – unit Volt (V)
  • current – unit Ampere (A)
  • resistance – unit Ohm (Ω)
  • frequency – unit Hertz (Hz)
  • capacitance - unit Farad (F)
  • diode test – voltage needed to overcome the PN-gap

It is important to be aware of how to measure a certain value properly without interfering or even damaging the multimeter or the circuit. All multimeters have different inputs for measuring current and voltage. The voltage input is protected with a high input impedance (> 1 MΩ). When measuring current, the leads act as a dead short so be very careful when using this mode and always plug the leads back into the voltage input so another person can't accidentally short a circuit when using the multimeter.

How to Measure

  1. think about what value you want to measure (voltage, current, resistance, …)
  2. check if the leads are connected to the right input (black to COM and red to relevant input)
  3. turn the dial to the correct mode
    1. select the right range (e.g. mV, V) - newer multimeters may have an autorange feature so they select the right range on their own as long as the correct input socket is used
  4. hold the leads to the two points you want to measure
  5. done!