A position measurement method is used by a device including an imaging unit and a position detector that detects a position of the imaging unit to measure, using a detection value at imaging of a measurement point, position coordinates of the measurement point. The method for correcting the detection value from the position detector includes obtaining, with the device, position coordinates of predetermined indices (22) arranged two-dimensionally on a calibration plate (20) as an actual measurement value, obtaining, as a correction value, a difference between the actual measurement value and a true value resulting from transformation of position coordinates of the indices (22) with respect to a reference point on the calibration plate (20), and correcting the detection value from the position detector (8, 9, 10). The imaging unit (3) images measurement points (P) on the measurement target (3) to measure position coordinates of the measurement points (P).

A surface sensing device is mounted on an articulating probe head of a coordinate measuring machine. The device includes an elongate probe holder which is rotatable about an axis. An elongate sensing module includes a surface finish or surface roughness probe with a stylus tip. This is connected to the probe holder via an adjustable knuckle joint. To determine the geometry of the surface sensing device, including the tip normal and drag vector of the stylus tip, the orientations of the probe holder and the sensing module are determined by probing points which are spaced along their lengths, using a separate probe.

A portable measuring device having: a measuring apparatus comprising a logic circuit and a reader, an accessory interchangeably connectable to the measuring apparatus and storing individual metrology information relative to the accessory in a form compatible with the reader, wherein the measuring apparatus is configured, while it is connected to the accessory, to: read the individual calibration information with the reader; acquire, using the accessory, a signal dependent from a metrology-related property of an object; convert the signal into a measure value in the logic circuit, using the individual metrology information of the accessory; output the measure value.

A position calibration system and method are disclosed, in which a control unit is provided to control a positioner sensing module to scan a circular positioner provided on a positioning substrate in a first direction and a second direction so as to acquire midpoints of two scanned line segments and acquire an intersection of lines extending from the two center points in a direction perpendicular to the first and the second directions as a calibration reference point, which correspond to a centroid (a center) of the circular positioner. The calibration reference point functions as a reference point for positioning the positioning substrate with respect to the positioner sensing module and is stored in a memory unit. The calibration reference point can be used as a positioning point during installation of a machine and can also be used for calibration of a position of the machine.

A calibration fixture that enables more accurate calibration of a touch probe on, for example, a CMM, with respect to the camera. The camera is mounted so that its optical axis is approximately or substantially parallel with the z-axis of the probe. The probe and workpiece are in relative motion, along a plane defined by orthogonal x and y axes, and optionally the z-axis and/or and rotation R about the z-axis. The calibration fixture is arranged to image from beneath the touch surface of the probe and, via a 180-degree prism structure, to transmit light from the probe touch point along the optical axis to the camera. Alternatively, two cameras respectively view the fiducial location relative to the CMM arm and the probe location when aligned on the fiducial. The fixture can define an integrated assembly with an optics block and a camera assembly.

An error determination apparatus for determining a measurement error that occurs when a workpiece is measured by a coordinate measuring machine, the error determination apparatus includes an information acquisition part that acquires a) motion error information indicating a result of measuring a motion error of the coordinate measuring machine and b) design information of the workpiece, a measurement position specification part that specifies a measurement position on the workpiece on the basis of the design information, an error determination part that determines a measurement error occurring in the measurement at the measurement position due to the motion error on the basis of the motion error information, and an output part that outputs the measurement error determined by the error determination part.

An error determination apparatus for determining a measurement error that occurs when a workpiece is measured by a coordinate measuring machine, the error determination apparatus includes an information acquisition part that acquires a) motion error information indicating a result of measuring a motion error of the coordinate measuring machine and b) design information of the workpiece, a measurement position specification part that specifies a measurement position on the workpiece on the basis of the design information, an error determination part that determines a measurement error occurring in the measurement at the measurement position due to the motion error on the basis of the motion error information, and an output part that outputs the measurement error determined by the error determination part.

In a workpiece production method a plurality of nominally similar workpieces are produced in a production process on one production machine. The order or time of production of some of the workpieces on the production machine is recorded. Some of the workpieces recorded are measured at two or more inspection stations. Dimensions or points of one workpiece are measured at one of the inspection stations, and corresponding dimensions or points of another of the workpieces are measured at another of the inspection stations. The results of the measurements of corresponding dimensions or points made at the two or more inspection stations are analysed together, taking account of the order or time of production of the workpieces. An output signal is produced based on the analysing of the results together. The output signal indicates performance of the production machine or of one or more of the inspection stations.

In a workpiece production method a plurality of nominally similar workpieces are produced in a production process on one production machine. The order or time of production of some of the workpieces on the production machine is recorded. Some of the workpieces recorded are measured at two or more inspection stations. Dimensions or points of one workpiece are measured at one of the inspection stations, and corresponding dimensions or points of another of the workpieces are measured at another of the inspection stations. The results of the measurements of corresponding dimensions or points made at the two or more inspection stations are analysed together, taking account of the order or time of production of the workpieces. An output signal is produced based on the analysing of the results together. The output signal indicates performance of the production machine or of one or more of the inspection stations.

A three-dimensional measuring device comprising an arm having a free end provided with an interface body that includes a front face that has projecting therefrom a tubular coupling part for coupling to a first measuring member for measuring by contact and that is arranged to form a fastener plate for fastening either to a first grip member or else to a second measuring member, and the interface body also includes a side surface arranged to form a second fastener plate for fastening to a second grip member.