- Tof instruments
From the mass differences generated in a calibration report, an algorithm generates a best-fit calibration curve as a fifth-order equation. Data peak points will not fall exactly on this calibration line; they will be scattered around. Each data point is assigned a residual mass value as the vertical distance between the data point and the calibration curve. Some residual will be positive (above the calibration line), some will be negative (below the calibration line), and some might be equal to 0 (positioned on the calibration line).