Calibrations can be linear, logarithmic, single-line, and multi-line fit.
The calibration method used depends on the method required.
pH and Color calibrations are linear, single-line fit calibrations.
Conductivity and Turbidity calibrations are multi-line, linear type calibrations.
ISE (Fluoride, Chloride, Ammonia, etc.) use a logarithmic multi-line calibration type.