Piezo-electric stretching detector and method for measuring stretching phenomena using such a detector

摘要

The present invention relates to a piezo-electric stretching detector which is used for measuring the positive and negative stretching on the surfaces of rigid structures using electric signals, wherein said detector can be attached by a force connection onto said surfaces in a compressible or non-removable relation. This stretching detector has a high sensitivity in all stretching directions and is made of a piezo-ceramic material which is applied in a thin layer on at least one surface of a flexible metal sheet or which is fixedly attached to said metal sheet in the shape of a moulded body. At least one of said stretching detectors can be arranged on the free abutting end of at least one resilient pressure body which is imbedded in the reception housing of a stretching sensor. The stretching sensor further comprises members for pressing the reception housing onto the surface to be measured. According to one method for measuring the positive and negative stretching on the surfaces of rigid structures using a stretching detector or sensor, the piezo-electrically emitted charges are amplified in charge amplifiers so as to obtain output signals which can be used by the controllers and have a voltage proportional thereto. The charge amplifier can also be switched rapidly from reduced charge ranges to very wide charge ranges.