Mikrometri

Mikrometri, or micrometry, is the branch of metrology that deals with measuring small dimensions. It covers methods for determining lengths, thicknesses, diameters, and distances at the micrometre scale, typically using instruments that provide a known scale or digital readout. Common contexts include materials science, biology, geology, and industrial metrology where dimensional accuracy at small scales is important. Measurements are usually expressed in micrometres (µm) or nanometres (nm) and are accompanied by an assessment of uncertainty and traceability to SI standards.

Measurement approaches include mechanical micrometry, optical micrometry, and calibrated imaging. A micrometer screw gauge (a mechanical instrument) converts axial movement of a spindle into a linear reading; standard models offer a least count of about 0.01 mm (10 µm) and higher-precision variants down to 0.001 mm (1 µm). Optical or instrumented micrometry uses an ocular reticle, stage micrometers, calibration grids, or software to compare the feature with known scale divisions. In microscopy, optical micrometry may use a stage micrometer or calibration by imaging a reference scale to determine magnification and size in the specimen image.

Practice emphasizes proper alignment, temperature control, and calibration. Uncertainties arise from instrument errors, magnification in imaging, and operator influence, and results are reported with an estimated confidence interval and traceability to national or international standards. See also micrometer in the instrument sense, stage micrometer, and optical micrometry.