Patent ID: 8198888
Filing Date: 2012-06-12
Classification: G01B

Abstract:
1. A method for determining the distance of a conducting surface profiled in a direction of distance determination, from a functional surface moving relative to the profiled surface, using a measuring arrangement, the method comprising: connecting a sensor, including a first and a second measuring coil for generating an alternating electromagnetic field, on its input side to an oscillator arrangement, and connecting on its output side by its outputs, which provide a first and second measurement corresponding to the distance between the profiled surface and the first and second measuring coil respectively, to an analog-to-digital converter unit via a demodulator unit to obtain first and second digital measured values corresponding to the first and second measurement; connecting an arithmetic unit to the analog converter unit, wherein the sensor includes a second measuring coil arranged at a known distance from the first measuring coil on that side of the first measuring coil that faces away from the profiled surface; and calculating via the arithmetic unit, using the first and second digital measured value and a reference digital value and the fixed distance, a distance measured value giving the distance of the functional surface from the profiled surface, the reference digital value corresponding to the measured value from a reference coil assigned to the measuring coils and located outside the range of influence of the profiled surface, wherein the arithmetic unit is used to determine a distance measured-value d giving the distance of the functional surface from the profiled surface using the equation where N 1 is the first digital measured-value, N 2 is the second digital measured-value, N 3 is the reference digital value, and a is the fixed distance.