MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS

**Definition:** This place covers:

Instruments and methods for measuring:

Methods of measuring geometrical parameters of objects (e.g. shape or surface configuration, measurement of volume, coordinates, height, length, width, thickness, contours, surface roughness or evenness, diameters, roundness, eccentricity, angles, alignment, deformation, displacement), devices for carrying out these methods and related calibration aspects.

Classification within G01B into the main groups is to a large extent based on the underlying measurement principle:

An exception is G01B1/00 , where documents should be classified which have aspects related to the material selected for the geometrical parameter measuring instrument.

Another exception is G01B9/00 , which is a hardware group mainly containing interferometers. Only when a distance or displacement measurement is concerned (or a related measurement, such as an orientation measurement based on distance measurements to various locations on the object), then an interferometer should be classified in G01B9/00 .

Small, hand-held mechanical devices (such as those available in hardware stores) are classified in G01B3/00 , whereas large mechanical set-ups (industrial machines, such as coordinate measuring machines) are classified in G01B5/00 .

To further support the user in consulting the main groups of this subclass, the following table summarises the properties of the electromagnetic spectrum together with the potentially relevant main groups.

**Glossary:** - Propagation effects: are relevant if the outcome of a measurement depends on the actual value of a physical quantity characterising the propagation of the wave, i.e. its wavelength, frequency, velocity, or phase. The mere presence or direction of a wave are not considered a propagation effect or to contribute to a propagation effect. To put it in another way, propagation effects are irrelevant, if the radiation may be looked upon as a beam of radiation whose wave nature can be ignored. Examples of measurements where propagation effects are relevant include, e.g. measurements of propagation time, phase difference, phase delay, measurements using the Doppler effect or interference. - Measuring areas: quantifying, by measurement, the size of areas (not: the act of measuring in certain spatial regions or the spatial regions where measurements are taken) - Irregularities of surfaces: smaller-scale surface textures - Contour: envelope-like description of (part of) the shape of an object