RESEARCH ON UNCERTAINTY EVALUATION FOR MATRIX METHOD OF MASS MEASUREMENT FROM 500 µg TO 50 µg

Jian Wang, Xiaoping Ren, Cai Changing, Nan Yang
Abstract:
Subdivision comparisons of mass measurement are usually used in the mass dissemination for class E1 and E2 mass standards from 1 kg to 1 mg or from 1 kg to 50 kg. Many equations of mass measurement are included in the subdivision comparisons. It is not easy to calculate values of true mass or conventional mass and the budget the uncertainty of subdivision comparisons by hand or Microsoft Excel software. Matrix calculations used in the subdivision comparisons of mass measurement are very convenient to get the true mass value or conventional mass value of every weight compared. Due to some matrixes used in the calculations, it is difficult to obtain directly the uncertainty budget of matrix method. Matrix method with uncertainty budget for measuring mass from 500 µg to 50 µg is proposed in the paper. Automatic mass comparator a5 is used to measure mass of microgram weights by matrix method of subdivision comparisons. All equations of subdivision comparisons are converted into expression of matrix. Another method for evaluating uncertainty of matrix equations that is Monte Carlo method in the paper is introduced in order to validate the calculation of uncertainty budget by means of matrix method. The values and uncertainties with respect to sets of microgram weights are calculated by programs self-developed under Mathcad software.
Keywords:
matrix method, mass measurement, subdivision comparisons, microgram weights, Monte Carlo method
Download:
IMEKO-WC-2015-TC3-075.pdf
DOI:
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Event details
Event name:
XXI IMEKO World Congress
Title:

Measurement in Research and Industry

Place:
Prague, CZECH REPUBLIC
Time:
30 August 2015 - 04 September 2015