World Metrology Day is celebrated by over 80 countries each year on 20 May - the anniversary of the signing of the Metre Convention back in 1875. To this day, the agreement provides the basis for a single, coherent system of measurements that are traceable to the International System of Units (SI).
The theme for World Metrology Day 2016 is: Measurements in a dynamic world.
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Measurements in daily life
Find out how measurement plays a vital role in all our lives.
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Measurement is beautiful:
A selection of images taken by NPL scientists
A mirrored 100 micron atomic force microscope (AFM) topographic image of ordered sub-micron structures.
Calibration of a step gauge.
A theoretical representation of the measurement of a star pattern using an optical imaging microscope: The resolution of the microscope is 300 nm but super-resolution techniques have been used to enhance this to 230 nm.
Adhesion map of epitaxial graphene on silicon carbide: The blue/green colour indicates single layer graphene, which preferentially absorbs environmental species, and the yellow colour indicates double layer graphene.
Magnetic Force Microscopy image of a novel magnetic nanosensor: The magnetic configuration is dominated by two 'magnetic vortices' located in the disk-shaped structures; the L-shaped structure is a permalloy nanowire.
Scanning spin gate microscopy image of a graphene Hall cross: The image is strongly dominated by electrostatic signals located in the corners of the device.
Mapping of magnetoresistance in permalloy nanodevices: Only two resistive states are possible: the red colour corresponds to the state without a domain wall (high resistance), and blue colour - to the state with a domain wall (low resistance).