FBG Strain Gauge OFSG-10A/OFSG-10B

OFSG-10These are strain gauges utilizing a FBG (Fiber Bragg Grating) optical fiber sensor. Taking advantages of the FBG sensor, the FBG strain gauge is applicable to the conditions to which conventional strain gauges cannot meet. They are most suited to strain measurement in the vicinity of a motor or transformer which may cause electrical noise, and also suited to strain measurement in petrochemical, natural gas or chemical plant or in hydrogen environment where explosion protection is required.


  • Temperature compensation function provided
  • Not influenced by electromagnetic noise
  • Connection of two or more gauges possible for both-end connector type OFSG-10B
  • Direct reading in strain by combined use with fiber-optic strainmeter TFM-104
  • Easy to handle (same as a strain gauge)
  • Measurement objects are steel, concrete and FRP such as composite material

Measurement principle

The wavelength of the light reflected by FBG varies depending on the strain and temperature. When the FBG is mounted on a measurement object, not only the strain generated on the object but also an apparent strain caused by the temperature change is measured. Therefore, appropriate temperature compensation is required when the temperature change is significant. The FBG strain gauge OFSG-10A/OFSG-10B is composed of two FBG sensors, one of which is for strain measurement and another is for temperature compensation. These two sensors have different center wavelength respectively. It is constructed that the sensor for temperature compensation is not influenced by the strain generated on the measurement object. Owing to this construction, apparent strain component caused by temperature change is correctly measured and rejected, and the strain generated on the object can be measured in excellent precision.


Type OFSG-10A OFSG-10B
Measurement object Metal, Concrete, Composite materials
Backing material Metal backing
Applicable adhesive Spot welding.CN.EB-2
FBG optical fiber specifications FBG length(mm) 10
Center wavelength(nm) Approx.1530 ~ 1565
fiber Polyimide coated single mode optical fiber
Operating temperature range(°C) -30 ~ +80
Cable length(mm) Approx.90
Connector assembly SC/APC
Number of connectors 1 2

Usage example of FBG strain gauge

A dedicated “Spot welder W-50R” is necessary when mounting the OFSG-10 by spot welding

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