Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.
Uncertainty budget of the literature values of Si5U3
Value
Unit
Printed
Reading
Method (class, basis)
Composition
Scatter
Conversion
Effective
-44.26
kJ/mol-atom
0.005
3.9 (model_calculated, calibrated)
3.9
-42.9
kJ/mol-atom
0.05
3.9 (model_calculated, calibrated)
3.9
Sources
A. Berche, C. Rado, O. Rapaud, C. Guéneau, J. Rogez, Thermodynamic study of the U–Si system, Journal of Nuclear Materials 389, 101-107 (2009). doi:10.1016/j.jnucmat.2009.01.014