| 摘要 |
PROBLEM TO BE SOLVED: To provide a method in which the composition and/or the moisture content of concrete are decided on the basis of the relative permittivity of the concrete without a need of a knowledge about a material to be inspected and without a need of the preparation of the material. SOLUTION: When the relative permittivityεr of a concrete is measured, radar waves are radiated toward the concrete block, a radar signal which is reflected by an object in the concrete block is detected, and its detection signal is signal-processed and evaluated. At this time, in a state that a radar transmitting antenna 2 and a receiving antenna 3 are positioned, the crosstalk signal of the radar waves radiated toward the concrete block from the transmitting antenna is detected by the receiving antenna. In addition, in a prescribed time window, an amplitude change which depends on a frequency in its spectrum is processed on the basis of a prescribed algorithm, preferably on the basis of an autoregressive model, and the relative permittivityεr is decided.
|
