Abstract: A measuring body is provided in a fluid path between a pump and a fuel injection valve, a flow amount for which is measured. An inner space of the measuring body is divided into a first and a second fluid chambers by a partitioning wall, wherein the first and second fluid chambers are, respectively, operatively connected to the pump and the fuel injection valve. A movable member (float) is slidably inserted into a through-hole formed in the partitioning wall, so that both ends are respectively exposed to the first and second fluid chambers. When the fuel injection is carried out by the fuel injection valve, the fluid in the second fluid chamber is decreased corresponding to the amount of injected fluid, and thereby the float is moved in a direction from the first to the second fluid chamber. The amount of the injected fluid is measured by detecting the movement of the float.

Abstract: A measuring body is provided in a fluid path between a pump and a fuel injection valve, a flow amount for which is measured. An inner space of the measuring body is divided into a first and a second fluid chambers by a partitioning wall, wherein the first and second fluid chambers are, respectively, operatively connected to the pump and the fuel injection valve. A movable member (float) is slidably inserted into a through-hole formed in the partitioning wall, so that both ends are respectively exposed to the first and second fluid chambers. When the fuel injection is carried out by the fuel injection valve, the fluid in the second fluid chamber is decreased corresponding to the amount of injected fluid, and thereby the float is moved in a direction from the first to the second fluid chamber. The amount of the injected fluid is measured by detecting the movement of the float.