Patent ID: 6011391
Filing Date: 2000-01-04
Classification: G01B,G01D

Abstract:
A measurement probe for measuring thin layers on a base material using a magnetic or eddy current process with tubular probe housing (5) with face-side lower opening (5a) for measurement sensor (12) with measurement pole (13) which is located on the bottom end of guide means (3) which is guided to move in the longitudinal axis of probe housing (5) against spring action as limited by a stop, in the initial position or rest position of measurement sensor (12) stop (9) on guide means (3) interacting with abutment (9a) on the probe housing, characterized in that above abutment (9a) sliding element (2) for measurement sensor (12) is guided to move on probe housing (5) as limited by a stop, and that in the path of the force between sliding element (2) and measurement sensor (12) there are two interacting helical springs (4, 10) with differing spring force which are dimensioned such that in the initial position of measurement sensor (12) the spring force of one helical spring (4) is less than the spring force of other helical spring (10), such that when sliding element (2) is actuated first one helical spring (4) is tensioned until its spring force overcomes the opposing force of other helical spring (10) and in this way guide means (3) with measurement sensor (12) is moved first against the action of other helical spring (10) from the withdrawn rest position into the measurement position, after the latter being reached further pressure on sliding element (2) is elastically captured by the first helical spring (4).