Towards the Distributed Temperature Sensor with Potential Characteristics of Accuracy
The idea behind this paper was stimulated by known of the theory of automatic control definition concern potential pulse characteristics. It is used for increase of metrological accuracy of the distributed temperature sensor. All known works used averaging of the pulse response or its processing on certain algorithms for reduction of an error of transformation. It is bad idealization of used pulse signals for simplification of calculations. Thus it is supposed by default that risetime and decrease of pulse top do not influence to accuracy. The given approach does not consider an error due the transitive characteristic for any signal transferred through system with finite number of elements. It is shown that in actual life it mismatches the validity. A new distributed temperature sensor structure with the characteristics nearly to so-called potentially achievable is proposed. It is offered to use the mathematical theory of potentially achievable pulse characteristics for definition of limitations of accuracy of the pulse converter. Thus our approach is a refusal of signal idealization otherwise use the constructive methods of approximation. The new approach allows to consider transient parameters: the risetime duration, cut-off, deadtime, and peak overshoot. In turn, it minimized an error related with methods of temperature calculation. For modeling the reflected signal is presented in the form of Lanne polynomials. The second polynomial Remez algorithm has been used for finding of peak overshoot. Finally, in the paper the operation principle of distributed temperature sensor is resulted. The methods related decreasing of noise influence to measurement are designated. Some practical advice on increase accuracy of measurement by distributed temperature sensor is given.