Messchargen

Messchargen is a German term used in metrology to denote standardized charges employed as calibration references for instruments that measure electric charge. The plural form reflects that multiple reference charges may be used across different ranges or instruments. In practice, a Messcharge is realized as a well-characterized quantity of electric charge whose value is traceable to the International System of Units (SI) via national metrology institutes such as the Physikalisch-Technische Bundesanstalt (PTB) in Germany or equivalent organizations elsewhere.

Realization methods typically rely on known-capacitance techniques: a precisely characterized capacitor is charged to a defined voltage, producing a charge Q = C·V that serves as the reference. Alternative approaches may involve controlled current generation over a defined time interval, or calibrated charge injection into a detector system. The key requirements for Messchargen are stability, reproducibility, and traceability, with environmental controls limiting leakage currents and dielectric absorption.

Applications include calibration and performance verification of charge-sensitive instruments such as electrometers, picoammeters, and low-current measurement setups; calibration of ionization chambers used in radiation dosimetry; and quality assurance in laboratories performing charge measurement. In some contexts the term may also refer more generally to calibration batches used for measurement experiments, or to standard samples used to verify instrument response.

See also metrology, calibration, coulomb, electrometer, SI units, PTB, BIPM.