Multi-cell sonic sensor
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The VÖGELE multi-cell sonic sensor is highly versatile. By calculating an average, it can compensate for brief irregularities in a reference. The sensor is capable of scanning not only the ground, but also references such as a tensioned wire or even a tensioned rope with a minimum thickness of 2.5 mm. For this purpose, the sensor is positioned perpendicular to the direction of motion, i.e. rotated through 90° compared to “Ground mode” position. The screed operator switches from “Ground mode” to “Stringline mode” at the press of a button in the Niveltronic Plus menu. After that, an average is no longer calculated; only the sound cone closest to the reference is used for grade control. In this mode, a reference can be copied on a 1:1 basis just as with the single-cell sonic sensor.
The single-cell sonic sensor emits just one sound cone and consequently copies references 1:1 without calculating an average. This allows a wide variety of references to be scanned, with the sensor easily adapted to suit different job site conditions. It is also characterized by the speed and ease with which it is installed and operated.
On this sensor, the value for temperature compensation is determined with the aid of a metal bow located a fixed distance from the sensor. Part of the sound cone reaches this bow and measures the distance. If the value measured deviates from the actual value, the difference serves as a correction value for the sensor.