Abstract
Measurements of void fraction by probe method have been the subject of a number of recent reports, which have used the principle of measuring the void ratio in terms of the time ratio of gas-phase existence.
The paper describes the principle of void ratio measurement based on the gasliquid volume ratio by measurements of local void velocity with single type probe. The difference between the values based on the gas-liquid volume ratio and the gas-phase existence time ratio is explained from such factors as the local void velocity fraction.