The conventional single-ended measuring configuration has been faced with the difficultly of accurately measuring temperature, due to ununiform attenuation distribution along the optical fiber sensor length. Loop Configuration using double-ended measurement, in which the laser pulses are injected into the fiber cable alternately from both ends, resolves these difficulties by automatic cancellation of the cable attenuation. Loop Configuration is, therefore, indispensable in applications where there is high fluctuation of cable temperature, such as in fumace applications, LPG leakage monitoring and areas of radioactibity.

Our NK-OPTIS system solves the problem with a unique loop configuration.
Its is applicable for measuring the temperature distribution for high-temperature plants, and for marine and geological surveys accurate to within ±1°C. The loop configuration has the further advantage in that, even in the unlikely event of an optical fiber break, the system can continue the measurement without interruption.