| 摘要 |
An electronic stethoscope for safety vibration analyses, having two vibration sensors (pickups) (1a, 1b) each with a piezoelectric element which is preferably mounted in a spring-loaded and vibration-free fashion in air cushions. The electric signals of the piezoelectric elements are conditioned in two separate channels which respectively preferably have low-noise preamplifiers (2a, 2b), a digital filter (6a, 6b) and an output amplifier (9a, 9b), and are respectively fed via a switch (10) to a transducer element (11a, 11b) of an electroacoustic transducer or to the two transducer elements of the electroacoustic transducer. The digital filters, which can be adjusted in wide ranges with respect to their filter characteristics and filter steepness as well as the filter frequencies ensure an excellent selective detection even of weak signals having a substantial interference signal level, in conjunction with a good locating possibility due to the two-channel processing. Selection can be improved by means of a balance controller (7). <IMAGE>
|
