Octane number of gasoline is a very important quality index of gasoline. Octane number is an agreed value representing the anti-knock performance of ignition engine fuel. And it is a conditional unit representing the anti-knock performance of gasoline fuel. The anti-knock ability of gasoline refers to the ability of gasoline to avoid knock. When it is burned in the engine. It not only represents the anti-knock performance of gasoline, but also represents the ability of gasoline to prevent knock. When it is burned in the engine. Knock refers to the phenomenon of abnormal combustion of gasoline in the engine. And there are many factors that cause knock in the engine. In addition to the excessive load and overheating of the engine, the mismatch between the compression ratio of the engine and the gasoline grade is the main factor causing knock.
Therefore, the octane engine must be used to determine the gasoline.
Octane number mainly includes motor octane number (MON), research octane number (RON) and road octane number. At present, research octane number is used as the trademark of gasoline in China. According to the octane number of the research method, gasoline is divided into three grades: 90, 93 and 97. In addition, there are three suggested brands: 89, 92 and 95.
The octane number of the research method can be determined by a specially designed single-cylinder engine with continuously varying compression ratio. In a standard engine test under specified conditions, the detonation strength of the sample is measured by comparing it with the standard fuel with which the octane number is known. The octane number of the reference fuel which is equivalent to the detonation intensity of the sample is expressed by the volume fraction of isooctane in the standard fuel. Which has the same anti-detonation property as the tested fuel. In addition, the gasoline infrared analyzer can also determine the octane number of the research method by measuring the insulation permeability of the sample, the charge characteristic of the electromagnetic induction and the dielectric characteristic of the sample, and then comparing with the built-in parameters.