In order to improve the accuracy, all kinds of calibration methods were used, for example, the internal calibration、solid-liquid standard calibration、dried aerosols calibration、liquid ablation calibration、normalization calibration and so on, but the internal calibration was the most popular method up to now.

This paper presents a high-precision camera calibration technique,which uses a virtual stereocalibration pattern formed by an infrared light-emitting diode(IR LED) moving along the pre-defined path on CMM.

The six-port reflectmeter calibration technique is the method of confirming the system constant of six-port measurement equipment.

The basic procedures of matrix normalized calibration were as follows:all measurable elements were determined by simple external standardization in the first step,and then the sum of all major element oxides were normalized to 100% to get the sensitivity correction factor which is used to correct all results of .

The self-calibration technique used in high precision data-collecting system is discussed.

In recent years a method called "Nose-to-Nose" calibration procedure is not limited by the bandwidth,but it is only suitable for some of the sampling oscilloscopes calibration.