| 摘要 |
<p>In the method and means disclosed, an energy source applies energy of varying magnitude, to a substance being tested, and in a sufficient amount to produce detectable variations in a surrounding fluid. The frequency of the energy is varied. A pickup in the vicinity of the sample responds to the detectable variations and produces electrical signals corresponding to the detected variations. A display indicates the intensity of the electrical signals at the different energy frequencies.</p> |
