Quickly verify fiber activity, polarity, and connectivity with the FiberLert™ Live Fiber Detector. This pocket-sized tool tests single-mode, multimode, UPC and APC patch cords and ports with a non-contact / non-contaminating detector. The LightBeat™ feature flashes the LED, indicating a powered-on condition and good battery, a timer shuts FiberLert™ off after five minutes of inactivity to extend battery life (2xAAA, included). Rugged design includes a convenient pocket clip and is backed by a two-year warranty.


Check polarity and operation of patch cords.

Determine if a port is live. Small size makes it easy to access cramped patch panels.

Determine if a transceiver is operational. FiberLert can detect fiber signals without making contact.
| Feature | Description |
|---|---|
| OPERATING PRINCIPLE | Senses near infrared light emitted from fiber optic cabling. A continuous red glow at the handle and an audible beeping noise (if not switched off) indicates the presence of near infrared light. |
| OPTICAL INTERFACE | Non-contact ceramic ferrule. Fits directly with 1.25 mm LC receptacles. Tethered ferrule adapter for testing 1.25 mm ferrule patch cord. Supports single-mode, multimode, UPC and APC connectors and ports. |
| WAVELENGTH DETECTION | 850 nm to 1625 nm |
| OPTICAL POWER DETECTION RANGE | +3 dBm to -30 dBm |
| LIGHT DETECTION | Visible steady red LED indicator when optical power is detected |
| LIGHTBEAT™ INDICATOR | Flashes twice every two seconds when unit is on and battery strength is sufficient. |
| BATTERY SAVER | Unit automatically turns off after five minutes of inactivity |
| BATTERIES | 2 AAA alkaline batteries included |
| BATTERY LIFE | Typically, greater than 1 year (5 hrs. of use a week) |
| ITEM SIZE | 0.6” x 1.0” x 6.6” / 1.6 x 2.5 x 16.8 cm |
| ITEM WEIGHT | 2.1 oz / 59 g |
| OPERATING TEMPERATURE RANGE | -10 °C to 50 °C |
| OPERATING HUMIDITY RANGES | 95 % (10 °C to 35 °C) Non-condensing 75 % (35 °C to 40 °C) Non-condensing uncontrolled < 10 °C |
| OPERATING ALTITUDE | ≤ 3000 meters |
| STORAGE TEMEPERATURE | -20 °C to 50 °C |
| Model | Description |
|---|---|
| FiberLert™-125 | FIBERLERT, 850 NM TO 1625 NM LIGHT DETECTOR |
| FiberLert-125 6P | 6 Pack - FIBERLERT, 850 NM TO 1625 NM LIGHT DETECTOR |