Mass standards and normal weights: The classes E0, E1, E2
General: Test weights are divided into different accuracy classes. From E0 (most accurate) via E1, E2, F1, F2, M1, M1-2, M2, M2-3 to M3 (most inaccurate). It can be said that the further ahead the letter is in the alphabet and the smaller the following number is, the more accurate the respective weight is. These weights, which are classified according to error margins (OIML), are used for various purposes, depending on production accuracy or permissible variations in mass.
The classes E0, E1 and E2 are called normal weights. They are used for traceability to national standards (E0) and are used for the calibration of high-precision scales (E1) or precision scales of class I (E2). Read more...
Class E0 (the main mass standards)
These weights are normally not used for scale calibration, but rather for traceability (calibration) of class E1 (mass standards) weights to national standards. The weights themselves represent the national standard or are required to represent the national mass scale up to 50 kg. Due to this high precision and the immense demands during production, E0 weights are particularly expensive.
Class E1 (mass standards)
Class E1 weights are used for comparative measurements with mass comparators. Or when high-precision scales (with a number of steps > 1 000 000 according to DIN EN ISO 9001ff etc.) have to be adjusted, tested, officially verified or calibrated. Thus, they serve to ensure quality at this high level. Weights of class E2 according to OIML R111 and E08 are also calibrated and officially verified using E1 weights.
Class E2 (standard weights)
Class E2 standard weights are adjustment, test, official verification and calibration weights for Class I precision scales and are used for quality assurance of scales with a number of steps < 1 000 000 according to
DIN EN ISO 9001ff etc. and for weighing or comparative measurements on class l scales or on mass comparators. Class F1 and F2 weights according to OIML R111 and E08 are calibrated and officially verified with their help.
The weights are not marked with their nominal value or with information regarding the unit. For differentiation purposes, weights of the same nominal value that are present several times in a set are marked with dots or asterisks. In addition, a maximum of three user characteristics (characters, letters and numbers) can be applied to uniquely identify the weights as test or measuring instruments.
These user characteristics can be specified by the customer when ordering.