Position: A new weighing equipment calibration methodology is introduced that uses the determination of systematic error and measurement uncertainty of the balance across its range. Method applies to single-range, multiple-range and multi-interval electronic balances. This calibration method introduces idea of designing and building of new generation high-resolution electronic weighing machines.
A Greek inventor offers a Weighing Controller calibration methodology that uses the determination of systematic error and measurement uncertainty of the balance across its range. Method applies to single-range, multiple-range and multi-interval electronic balances. This calibration method introduces idea of designing and building of new generation high-resolution electronic weighing machines. Companies involved in weighing equipments are requested for technical and commercial collaboration.
The calculated measurement uncertainty is based on the following parameters:
1. Repeatability
2. Resolution
3. Eccentricity (off-centre loading)
4. Deviation of indication – Linearity
5. Drift of Weighing Controller
6. Effect of convection
7. Standards weights and density of air
8. Hysteresis
Innovative Aspects:
Innovative aspects in this calibration methodology are:
1. The calculation of uncertainty during eccentric loading of the balance.
A new distribution has been introduced (A- priori distribution) of density of probability - an indication in the balance that corresponds to real measuring conditions. This distribution has been solved and standard uncertainty of the eccentricity has been incorporated into the final uncertainty budget.
2. Calculation of the systematic error, which has introduced for the first time the term conventional weighing indication value and calculation into international bibliography of standard systematic uncertainty, which is a contribution of systematic error to measurement uncertainty.
3. Calculation of the standard uncertainty of the density of air and its incorporation into the uncertainty budget.
4. Calculation of measurement uncertainty and systematic error during loading and unloading of the balance, bearing in mind the results of hysteresis.
5. Determination of the measurement uncertainty in weighing an object on a balance that has been calibrated using the present method.
Main Advantages:
The present methodology contributes so that the reliability of weighing remains a challenging priority aiming at the best documentation of the measurement result.
The main advantages are:
1) best exploitation of balances
2) improved quality upgrading of the procedures based on weighing
3) more rational compliance or not with conformity specifications, as well as
4) reduction of profit losses due to inaccurate weighing of products
To achieve the above the following are necessary:
1. Measurement of environmental conditions (air temperature, air atmospheric pressure and air humidity) during weighing.
2. Introduction of the results of previous calibrations with this method for the balance in question.
3. Introduction of data for the density of the object being weighed.
The above could be realised through the use of measurement appliances and software which are not immediately associated with the type of electronic balance.
In the future the meteorological station for measuring environmental conditions and the software could be incorporated into the weighing unit so that the determination of mass can be established with simultaneous indication of the measurement uncertainty on the balance’s display, while there may be the possibility of further processing of the measurement results.