Calibration is the process by which we can adjust the value to be more accurate and precise compared to the known reference calibration standard. Calibration is also used to correct the offset error of the instrument.
One Point Calibration:
One Point calibration is the simplest and easiest calibration procedure. If your instrument is only require single level calibration to adjust the value.
If the sensor of the instrument scaled and make the linear graph, only with the help on one calibration standard then one point calibration has used.
One point calibration helps to correct the offset errors of the sensor.
Two Point Calibration:
2 point calibration is the procedure where the instrument is calibrated in two different points with the help of two calibration standards. While the two point calibration, it adjusts the values and rescales the output graph, and corrects the slope and offset errors of the instrument.
The graph of two point calibration is linear, because it is calibrated only in two points.
Multi- Point Calibration:
Calibration of the instrument more than one or two point known as the multi-point calibration.
In some instruments not showing the linear graph against the measurement range, they require curve measurement to get the accurate measurement. In this situation multi-point calibration has used.
3 point, 5 point are also come under the Multi-Point Calibration.