Exfo LFD-250B Live Fiber Detector

The EXFO LFD-250B is a handheld live fiber detector that identifies active optical fibers non-intrusively using step-motor-activated macro-bending technology. The instrument detects signal presence and traffic direction, pinpoints dark fiber through tone recognition at 270 Hz, 1 kHz, and 2 kHz, and measures in-line optical power—all without disrupting network traffic or damaging the fiber.

Unlike traditional fixed-angle bending detectors, the LFD-250B continuously optimizes the bending angle to minimize insertion loss while maximizing detection reliability. The motor-controlled approach ensures insertion loss remains ≤1 dB across all singlemode telecom fibers and wavelengths, with the fiber automatically released when no signal is detected, preventing stress-induced damage.

– Technical Specifications

• Power Measurement Range: −35 dBm to +20 dBm
• Power Measurement Accuracy: 1 dB repeatability, achieved through insertion loss monitoring and exiting signal measurement with automatic coupling efficiency adjustment by jacket size
• Insertion Loss: ≤1 dB (guaranteed for all singlemode telecom fibers at all wavelengths)
• Tone Detection: 270 Hz, 1 kHz, 2 kHz
• Test Duration: <6 seconds
• Battery: Four AA alkaline or rechargeable cells; AC adapter available (indoor use only)

– Key Features

• Motor-controlled fiber bending optimizes detection for each fiber type and wavelength
• Traffic direction verification via dual LEDs (left LED indicates rightbound traffic; right LED indicates leftbound traffic)
• Ambient light offset with optional push-down cap for high ambient light environments
• Tone signal LED for 270 Hz, 1 kHz, and 2 kHz identification
• Locating LED that flashes when the clamping mechanism engages
• Battery status monitoring with low-battery indicator

– Compatibility & Integration

The LFD-250B accommodates 900 µm, 1.6 mm, and 3 mm jacket diameters. Use with caution on 250 µm fibers, as the clamping pressure may cause damage. The instrument is optimized for singlemode telecom fibers across all standard wavelengths.