Clamp an optical fiber identifier onto an unstripped fiber under test, apply a controlled bend, and read the device's display to confirm signal presence, direction, and relative power level — all without cutting or disconnecting the live link.

An optical fiber identifier works by detecting evanescent light that leaks slightly through a controlled bend in the fiber's cladding. You don't need to break the fiber or take the link down — the identifier picks up the signal passively. On the D YEDEMC fiber identifier, you clamp the device onto the fiber, select the wavelength window, and the display confirms whether a live signal is present and which direction traffic is flowing, which matters when you're tracing a specific fiber through a crowded splice enclosure or distribution panel.

  • D YEDEMC optical fiber identifier operates across an 800–1700nm detection range, covering both single-mode and multimode live fibers.
  • The D YEDEMC fiber identifier includes a built-in 10mW VFL, detectable over longer distances than the 2mW VFL in the portable power meter.
  • Optical fiber identifiers work on active fibers without signal interruption — traffic continues flowing during the test.
  • Acceptable live fiber power range for most passive optical links: −10 to −25 dBm on the identifier's relative power readout.
  • Fiber identifier connector compatibility on D YEDEMC models: FC, SC, and ST via universal interface adapter.

Step-by-Step

  1. Locate and expose the target fiber: Identify the specific fiber you need to test inside the splice enclosure, distribution panel, or cable run — don't strip the jacket or disconnect any connectors.
  2. Set the D YEDEMC identifier's wavelength window: Match the detection window to your fiber type — 1310/1550nm for single-mode FTTx or access network fiber; 850/1300nm for multimode in-building runs — before clamping to avoid a missed or ambiguous reading.
  3. Clamp the identifier onto the unstripped fiber: Open the jaw, seat the fiber into the V-groove, and close it firmly so the device applies a controlled bend — an incomplete clamp produces weak or no signal detection.
  4. Read the display for signal presence and direction: Confirm the live signal indicator is active, then note the directional arrow — on the D YEDEMC fiber identifier, direction helps you verify you have the correct fiber in a congested panel before doing any work.
  5. Check relative power level against the expected range: A reading between −10 and −25 dBm is normal for most passive optical links; a reading outside that range flags a potential problem on the span worth investigating further.
  6. Switch to the built-in 10mW VFL for break or bend fault confirmation: If signal presence is weak or absent, activate the D YEDEMC identifier's VFL to shoot visible red light down the fiber — a glowing spot through the jacket pinpoints a break or severe bend without needing an OTDR.