A “Load Line Calibration” (LLC) methodology for [0] in silicon determinations by SIMS is introduced. The LLC uses two (or more) p- silicon dice characterized by FTIR as calibration standards that are incorporated into each load of analytical samples. Repeated measurement of p- control samples with an [0] = 27.7 ppma [1] shows that with a two-point-LLC methodology the “load to load” relative error is 2.6% (σ = 0.7 ppma). Measurement results are presented and compared with those obtained by other calibration methodologies. The results have been obtained under experimental conditions that are adaptable for large scale production of controlled oxygen n+ and p+ silicon substates.