Page 10 of catalogue Linear inductive displacement sensors of Micro-Epsilon Messtechnik GmbH & Co. KG

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Technology and measurement principle
Electromagnetic Displacement sensors are used extensively in applications for automated processes, quality assurance, test rigs, hydraulics, Pneumatic cylinders, and automotive engineering. The advantages of these displacement Sensors are well known and highly valued, and include ruggedness, reliability under harsh conditions, high signal quality and good temperature stability. The electromagnetic sensors of the induSENSOR series are based on the well-proven inductive and eddy current principle. They are used successfully both in single and high volume OEM applications. The measurement ranges of the Micro-Epsilon Inductive sensors extend from a few tenths of a millimeter to over 600 mm. The actual measurement takes place without contact. The different measurement principles that can be offered are described below.

induSENSOR: VIP series and LVP series technology and measurement principle
VIP series and LVP series
The electromagnetic sensors in the VIP and LVP series operate using a novel, patented measuring principle. A measurement coil is wound on a coil former and has a number of voltage taps. For a measurement object a target is used of electrically conductive or ferro-magnetic material, the length of which corresponds to the distance between two taps on the measurement coil. The measurement coil is supplied with two complementary alternating voltages from an oscillator. Depending on the position of the target, the impedance of the measurement coil changes in the covered region. The tapped voltages are conditioned in an electronic evaluation unit which produces a continuous signal on its output which is proportional to the target position. If the target is located, for example, in the middle of the measurement coil, the output signal corresponds to the reference voltage.
up to 55% shorter construction LVP series length 176 mm common LVDT sensor length appr. 320 mm identical measuring range 100 mm

An very important advantage of sensors in the VIP series is a very compact sensor length to measurement range. Depending on the measurement range, the overall sensor length can be reduced by up to 55 %. This means that these displacement sensors can be integrated into a restricted space envelope in Machines and equipment, Hydraulic and Pneumatic cylinders and other applications. This opens up new possibilities for design engineers. In particular, in the measurement ranges from 20 to 200 mm the VIP measurement principle offers the greatest advantage of any sensor in terms of performance, length, accuracy and cost-effectiveness.

Advantages
- Easy adaptation to the measurement task through the use of non standard targets - Matching of the mechanical and electrical zero points for large-scale applications by laser trimming - Wide frequency range, up to 20 kHz -3db - Very low cost solutions for high volume applications

VIP series

target

With appropriate design of the target, circular paths can also be acquired with the VIP series.