Calibration of a weight of nominal value 10 kg
The calibration of a weight of nominal value 10 kg of OIML class M1 is carried out by comparision to a reference standard (OIML class F2) of same nominal value using a mass comparator whose performance characteristics have previously been determined.
Model Equation:
m_{X} = m_{S} + δm_{D} + δ_{m} + δm_{C} + δ_{B}

List of Quantities:
Quantity  Unit  Definition 

m_{X}  g  conventional mass of the unknown 
m_{S}  g  conventional mass of the standard 
δm_{D}  g  change of value of the standard since its last calibration due to drift 
δ_{m}  g  observed difference in mass between the unknown mass and the standard 
δm_{C}  g  correction for eccentricity and magnetic effects 
δ_{B}  g  correction for air buoyancy 
m_{S}: 
Type B normal distribution Value: 10000.005 g Expanded Uncertainty: 45·10^{3} g Coverage Factor: 2 
REFERENCE STANDARD: The calibration certificate for the reference standard gives a value of 10 000,005 g with an associated expanded uncertainty of 45 mg (coverage factor k=2)
δm_{D}: 
Type B rectangular distribution Value: 0 g Halfwidth of Limits: 15·10^{3} g 
DRIFT OF THE VALUE OF THE STANDARD: The drift of conventional mass of the reference standard is estimated from previous calibrations to be zero within limits ±15 mg
δ_{m}: 
Type A Method of observation: Indirect SUUS Number of observation: 3
Arithmetic Mean: 0.0200 g 
δm_{C}: 
Type B rectangular distribution Value: 0 g Halfwidth of Limits: 10·10^{3} g 
COMPARATOR: No correction are applied for the comparator whereas the uncertainty due to eccentricity and magnetic effects is estimated to have rectangular limits of ±10 mg
δ_{B}: 
Type B rectangular distribution Value: 0 g Halfwidth of Limits: 10·10^{3} g 
AIR BUOYANCY: No correction is made for the effects of air boyancy, the limits of deviation are estimated to be ±1.0·10^{6} of the nominal value
Uncertainty Budgets:
m_{X}: conventional mass of the unknown
Quantity  Value 
Standard Uncertainty 
Distribution 
Sensitivity Coefficient 
Uncertainty Contribution 
Index 

m_{S}  10000.0050 g  0.0225 g  normal  1.0  0.022 g  59.6 % 
δm_{D}  0.0 g  8.66·10^{3} g  rectangular  1.0  8.7·10^{3} g  8.8 % 
δ_{m}  0.0200 g  0.0142 g  normal  1.0  0.014 g  23.7 % 
δm_{C}  0.0 g  5.77·10^{3} g  rectangular  1.0  5.8·10^{3} g  3.9 % 
δ_{B}  0.0 g  5.77·10^{3} g  rectangular  1.0  5.8·10^{3} g  3.9 % 
m_{X}  10000.0250 g  0.0291 g 
Results:
Quantity  Value 
Expanded Uncertainty 
Coverage factor 
Coverage 

m_{X}  10000.025 g  0.058 g  2.00  95% (ttable 95.45%) 