Continuity testing overview

  • Continuity is the presence of a complete path for current flow. A circuit is complete when its switch is closed.
  • A digital multimeter’s Continuity Test mode can be used to test switches, fuses, electrical connections, conductors and other components. A good fuse, for example, should have continuity.
  • A DMM emits an audible response (a beep) when it detects a complete path.
  • The beep, an audible indicator, permits technicians to focus on testing procedures without looking at the multimeter display.
  • When testing for continuity, a multimeter beeps based on the resistance of the component being tested. That resistance is determined by the range setting of the multimeter. Examples:
    • If the range is set to 400.0 Ω, a multimeter typically beeps if the component has a resistance of 40 Ω or less.
    • If the range is set 4.000 kΩ, a multimeter typically beeps if the component has a resistance of 200 Ω or less.
  • The lowest range setting should be used when testing circuit components that should have low-resistance value such as electrical connections or switch contacts.