Our unique Cold Clamp locates fiber optic cable breaks & faults to a physical accuracy of better than 1 meter over long distance.

It causes a temporary optical loss marker at a location near the fault, allowing any mini-OTDR user to find the physical fault with great accuracy. 

In practice a fiber OTDR distance measurement is accurate to 0.5% - 2%. Real-world systems also often have cable coils & undeclared topologies that impact distance measurement. So a cable fault can be hundreds of meters away from an expected location, even when using best OTDR fault finding practices.

Diagram showing OTDR usage with a Cold Clamp

  • Works brilliantly over long distances on underground faults
  • Reduces network hazard and days of labor as exploratory trenching is eliminated
  • Minimizes community disruption and excavation damage
  • Find a hidden fault or break in fibre cables where there is no visible evidence
  • Minimizes service disruption, since it can be used on a live system
  • Economical repair allows revival of dark or abandoned fiber lines, reclaiming capacity
  • Inexpensive, non-destructive & field proven locator. Telcordia (Bellcore) report available
  • Use your existing training & OTDRs
  • Safety kit & work practices are provided. (a small amount of liquid nitrogen is easier to acquire and manage safely than most people think!)

Part Number Details

Part Number
Suited for
Starter Kit
Suited for
5 Cold Clamps & Consumables
Suited for
Work Kit
Suited for
10 Litre Dewar
Suited for
1 Litre Flask
Suited for
Not sure? Make a general enquiry.


General Cold Clamp specifications
Weight Empty 6.1 kg, Full 14.1 kg
Maximum Cable Diameter 38 mm
Known Applicable Cable types Fiber optic cable, jelly filled with acrylate coated fiber, including armoured types.
Typical loss created by Cold Clamp 0.21 dB at 1300 & 1550 nm
Typical usage of liquid nitrogen 300 ml (15mm non-metallic cable)
Liquid nitrogen boiling Point 196 °C
10-Liter Dewar 45 days of boil dry time in static conditions

Documentation & Support

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