Patent ID: 6715342
Filing Date: 2004-04-06
Classification: G01B

Abstract:
An apparatus for pneumatic length measurement comprising:a pre-nozzle; a measurement nozzle through which the medium used for the measurement is directed onto an impact plate; a first pressure sensor arranged in front of the pre-nozzle; a second pressure sensor arranged between the pre-nozzle and the measurement nozzle; means for determining the distance of the impact plate from the measurement nozzle based on the change in pressure (p2) between the pre-nozzle and the measurement nozzle while accounting for the pressure (P1) measured by the first pressure sensor; and means for determining the scale of the apparatus in a given measurement range, wherein the means for determining the scale operates with a function which assumes that the outflow number (Ã¿1) of the pre-nozzle and the outflow number (Ã¿2) of the measurement nozzle remain constant, so that the function used to determine the scale of the apparatus can be used with only one constant; wherein the calibration means uses the function x=p1p2-1Bâ€ƒas the calibration function, with B being a constant.