| 摘要 |
<p>PURPOSE:To accurately measure the temperature of an object which changes according to time or place by deciding whether the change of physical quantity in terms of time is easy or sudden based on the magnitude of a difference between a data group and a main data group obtained just before it with respect to a decision level. CONSTITUTION:Light pulse is made incident from one end of the optical fiber 4 and the distribution of the scattered light of a part along the optical fiber, that is, temperature distribution is obtained by a distribution type sensor which uses an OTDR method for detecting the backscattered light. Then, the data group D1 obtained by performing N1 times of averaging processing less than N0 times of averaging processing in which measuring accuracy in a state where a series of sampling and the change of physical quantity are temporally easy is high is conducted to an averaging processing selection device 2. The group D1 is compared with every data corresponding to the main data group D0 obtained just before it so as to generate a difference DELTAD, which is compared with the decision level so as to obtain a new data group based on the magnitude of the difference by averaging processing. Meanwhile, when the change is sudden, the measurement is performed by setting the data group D1 obtained by N1 times of processing as a new main data group. As a result, temperature distribution arithmetic display 3 is performed.</p> |
