| Popis: |
Investigation into the self‐noise of a SPOCAL (solion polarized cathode acoustic linear) transducer has identified the mechanisms responsible for this self‐noise. Measurements on this transducer have shown it to have a noise threshold of 10−5 μbar, or less than 10−8 mm Hg. Therefore, the linear dynamic range of this type of transducer is 100 dB in the pressure range from 10−5 to 10+3 μbar, with a frequency range from 0.0002 to 3 Hz. The noise thresholds of conventional liquid‐pressure measuring devices are several orders of magnitude higher than those of SPOCAL tranducers. The SPOCAL transducer has been applied in a seismometer where it senses the motion of a mercury column as the inertial mass. This SPOCAL seismometer obtains valid data from seismic activity at levels far below the capability of the instruments currently in use.Subject Classification: [43]85.24, [43]85.40; [43]40.50. |
