Sample Weight & Masses

Weights and sample masses certified in accordance with OIML R111: Classes M, F, E

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Certified sample weights to ensure regulatory compliance

Gibertini Elettronica supplies calibration weights and sample masses to quickly and independently perform calibrations on your laboratory instruments (Classes M, F or E), or control of approved scales (legal metrology) in the industrial sector.


How to choose sample weights

The International Organization of Legal Metrology (OIML) is a global intergovernmental organization whose primary objective is the harmonization of regulations and metrological controls applied by national metrology bodies, or by similar bodies of its member states. The internationally recognized OIML R111: 2004 standard divides sample weights into classes, where E1 is the most accurate case and M3 the least accurate.

Accuracy class Scale category Description Resolution
E1 I Semi and micro high resolution scales Beyond 500.000 d
E2 I High resolution analytical scales Beyond 100.000 d
F1 II Analytical / Precision scales up to 100.000 d
F2 II Precision scales up to 50.000 d
M1 II e III Industrial scales and approved scales up to 10.000 d

The accuracy classes of the masses used with weighing instruments must be chosen in accordance with the provisions of R 76 of the OIML "Non-automatic weighing instruments".

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OIML R111-1: 2004 Table of maximum permitted errors

The OIML R111 standard establishes the maximum permitted errors for the weights of the different classes according to the table on the side (± δm in mg). If the sample masses are used for calibration or verification of a balance:

  • it is necessary to use masses whose error is less than 1/3 of the instrument's division.
  • it must be ensured that the sample weights are certified, i.e. capable of providing accurate calibration results
  • The periodicity of the calibration of the sample masses varies according to the accuracy class, the frequency of use and the conditions of use

Classes & Materials

Weights can be supplied in fraction kits, weight sets or single masses. Gibertini offers sample masses from the OIML E1 to M3 class with the following characteristics:

Class Material Description
E1 Stainless steel wire fractions and cylindrical weights MEC from 1 mg to 10 kg
E2 Stainless steel lamellar fractions and cylindrical MEC weights from 1 mg to 10 kg
F1/F2 Stainless steel lamellar fractions and cylindrical MEC weights from 1 mg to 10 kg
M1 Stainless Steel / Chromed Brass lamellar fractions and cylindrical MEC weights from 1 mg to 10 kg
M1 / Metric Cast iron and steel masses from 5 kg to 50 kg
M1 Phosphated Iron Disc weights with weight holder from 1 kg to 20 kg


  • Single weight wooden containers / weight set
  • Single weight aluminum containers / weight set
  • Plastic containers single weight / weight set
  • Stackable Class M1 stainless steel cage (24 x 20kg)
  • Gloves
  • Tweezers

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