Measurement Errors

In everyday language, measurement deviations are often called measurement errors. Strictly speaking, however, measurement errors (mistakes) are only the part of the measurement deviations caused by incorrect handling of the measurement equipment. If the length of a 3 m long table is measured with a folding rule, a mistake would be placing the folding rule incorrectly when transferring the first folding-rule length of 2 m. The uncertainty of the length of the folding rule, on the other hand, has nothing to do with handling and is therefore not called a measurement error. If someone measures clumsily and thus causes additional measurement deviations, a measurement error occurs.