It should be noted that, in order to estimate the uncertainties of more than one variable, the same procedure can be used to determine the appropriate terms in Eqs. (12.39) and(12.40). A much easier way to determine uncertainties is to use a spreadsheet for the calculations. In this case, the change of one or more parameters in appropriate cells(e.g., cells containing i, d, iR etc.) causes automatic recalculation of the spreadsheet, and the new value of LCS is obtained immediately.