PVDF sensors can measure piston positions sturdily and inexpensive. By several one behind the other angereihte sensors piston positions can be seized quasi-similarly. (digitally from sensor surface similarly to sensor surface, within the sensor surface)
The patented procedure for the position control of pistons in hydraulic cylinders made a new generation possible of Low Cost sensors.
So far position measurements for pistons in hydraulic cylinders are made by laterally attached ultrasonic sensors with ceramic(s) oscillators. In addition usually modified sensors become, how them admit from the material testing (NDT) are used. These sensors are usually manufactured as cylinders. These possess a planar coupling surface at the face. This front surface cannot rest upon however full-laminar the curved cylinder wall. The contact to the cylinder surface takes place only on a very narrow strip toward the cylinder expansion. The contact can be improved by a ouple means somewhat. If these sensors are also pressed to large load against the cylinder wall, inevitably the sensitive Piezokeramic breaks.
If the position measurement is implemented laterally at the cylinder, the position sensors stand more usually reject laterally outward. Well-known sensors are to be installed mechanically so far only by clips or welded on fastening spots. Further they are exposed to possible damages by their dimensions.
The measurement of these sensors effected only point for point and is limited only to a position.
The new patented sensor arrays made of PVDF foil rest upon against it flat on the cylinder wall. The structure height amounts to less than 1 cm and by the housing and by the cable connection is essentially determined.
These piezoelectric elements are attached laterally on the hydraulic cylinder. These elements are flexible and adapt to the curvature of the hydraulic cylinder. With several arrays from PVDF foil also longer drives can be seized. Available PVDF foils cover a temperature range of -40° C to +100° C, with sensors from copolymers are attainable a temperature range to 145° C. Thus the ultrasonic sensors developed in the new patented procedure can be used also for applications, which require higher application temperatures. New application type result for these sensors in the case of the monitoring of pipings of small dimensions. In the biotechnology and active substance production often residue control is in demand. With small flexible tubing sensors, which adapt to arbitrary pipe diameters, the monitoring is economically possible of mini Plants.