172results about "Caliper-like sensors" patented technology

A device for measuring the thickness of a sheet or web product including at least one moveable measuring sensor which can be pressed against the product while forming an air pad between measuring sensor and product. At least one measuring sensor is respectively provided on both sides of the sheet or web product. The thickness of the respective air pad can be measured, the total gap thickness including the thickness of the two air pads and the product thickness can be measured. Elements are provided for calculating the product thickness by subtracting the thickness of the air pad on the two product sides from the measured total gap thickness.

A method for calibrating a thickness gauge, wherein the thickness gauge measures the thickness of a measurement object in a predefinable measuring direction (Z), comprising at least one displacement sensor (1, 2) operating in a contactless or scanning manner, wherein a reference object (3) having a known thickness and shape is moved into at least a partial region of the measurement field of the at least one displacement sensor (1, 2), comprises the following steps with respect to particularly precise and simple calibration. First, at least two independent measurement values are recorded by the at least one displacement sensor (1, 2) in at least two predefinable sites on a first surface of the reference object (3) at predefinable times tj, or as a function of predefinable positions pj of the reference object (3) in the measurement field, where j = 1, 2... Then the tilting or spatial position of the reference object in the measurement field is determined based on the measurement values recorded at the times tj, or as a function of the positions pj of the reference object (3). Then, a further measurement value is recorded by the at least one displacement sensor (1, 2) at a further site located in the measuring direction (Z) on a second surface disposed opposite the first surface, or on a surface region of the reference object (3) disposed opposite the first surface, in order to determine a thickness value of the reference object (3) in the measuring direction (Z).

A method and apparatus for moving an article relative to and between a pair of distance sensing probes of a thickness measuring apparatus which are spaced apart a known distance D is described. In the method, the article is moved relative to and between the pair of probes in at least one direction in a plane normal to a common measurement axis Ac between the probes. A distance a along the common measurement axis Ac between the first probe and a point on the surface of the article nearest to the first probe of the pair that intersects the common measurement axis Ac is measured. A similar distance b between the second probe and the article is measured. From the measured distance a, the article is moved relative to the probes along the common measurement axis Ac so as to minimize any difference between the measured distance a and a desired distance ad along the common measurement axis Ac between the first probe and a point on the surface of the article nearest to the first probe that intersects the common measurement axis. The measured distances a and b and the position of the article relative to the probes in at least one direction are recorded at predetermined time intervals to develop a thickness map of the article. In a thickness computation, all of the measured distances a for each recorded position of the article are substantially the same.

A method for measuring the thickness on measurement objects, whereby at least one sensor measures against the object from the top and at least one other sensor measures against the object from the bottom and, at a known distance of the sensors to one another, the thickness of the object is calculated according to the formula D=Gap−(S1+S2), whereby D=the thickness of the measurement object, Gap=the distance between the sensors, S1=the distance of the top sensor to the upper side of the measurement object, and S2=the distance of the bottom sensor to the underside of the measurement object, is characterized by the compensation of a measurement error caused by tilting of the measurement object and / or by displacement of the sensors and / or by tilting of the sensors, whereby the displacement and / or the tilting is determined by calibration and the calculated thickness or the calculated thickness profile is corrected accordingly. The invention further concerns a device for applying the method.

Upper to lower assembly analog position sensors in a dual scanning system measure alignment offsets. A controller uses error signals from the position sensors to calculate actuator error profiles that are used in the next scan in the same direction, with different error profiles being used for forward and reverse scans. Since the alignment error profiles are repeatable for a given set of scanner conditions, the actuator controller anticipates what the error signal will be before each scanning assembly reaches a given position. An optimized error correction can be calculated based on the error profiles and actuator bandwidth without concerns regarding feedback loop speed, overshoot, and unstable control oscillations. An actuation system driven from error profiles can correct for alignment offsets by actively changing belt tensions at the offsetting drive pulleys and / or changing the position of sensor assemblies relative to the drive belt systems.