The oil chromatography analyzer under UHV power can help many power workers conduct various power tests more conveniently.

The gas chromatograph temporarily separates the mixture on the chromatographic column, and then sequentially detects the separated components using a detector. The diameter of the column is a few millimeters, filled with solid adsorbent and liquid solvent called stationary phase.

There is also a corresponding fixed mobile phase. The mobile phase is a gas that does not react with either the sample or the stationary phase, typically nitrogen or hydrogen. The sample of the analysis object is injected into the front end of the chromatographic column by the mobile phase, and the sample is brought into the chromatographic column, so the mobile phase is also known as the carrier gas.

The carrier gas flows through the chromatographic column at a continuous flow rate during the analysis process. Inject the sample once and obtain the analysis results each time.

The separation of samples through chromatographic columns is based on differences in thermodynamic properties. The affinity between the stationary phase and the components in the sample varies (due to differences in gas chromatography adsorption capacity and gas-liquid distribution chromatography solubility). When the carrier gas continuously carries the sample through the chromatographic column, the components with high affinity slowly move in the chromatographic column. Because high affinity means relatively high tension relative to a fixed level. Small affinity for rapid movement. The four cylindrical tubes are actually one, used only to represent the states of various components in the sample at different times.

The sample is a mixture of a, B, and C. After the carrier gas enters the chromatographic column, the three are completely mixed, as shown in state (I). After a period of time, when the carrier gas carries a certain distance in the chromatographic column, the three begin to separate, as in state (ii).

Furthermore, like states (iii) and (iv), these three are separate.Their fixed affinity is A>B>C, so their movement speed is C>B>A. 

The detector provides signals corresponding to each component of the input. Inject the sample into the carrier gas as the starting point for timing. After separation, each component enters the detector in sequence. The maximum signal (often referred to as peak) corresponding to each component provided by the detector is called the retention time TR of each component.

In fact, it has been proven that the retention time (TR) of different components is also constant under certain conditions, including carrier gas flow rate, material and properties of the stationary phase, column length, and temperature.

Therefore, the composition of the substance can be inferred based on its retention time. Therefore, retention time is the basis for qualitative analysis of chromatographic instruments.

The signal from the detector to each component displays a peak in the recorder, which is called the chromatographic peak. The maximum value on the chromatographic peak is the basis for qualitative analysis, while the area of the chromatographic peak depends on the content of the corresponding component, so the peak area is the basis for quantitative analysis.

The curve recorded by the recorder after injecting the mixed sample is called a chromatogram. Qualitative and quantitative results can be obtained by analyzing chromatograms.