INJECTION QUANTITY METER

PROBLEM TO BE SOLVED: To provide an injection quantity meter for continuously metering every injection quantity of fluid with accuracy without influencing the spray form of fluid. SOLUTION: A light sending system S sends a laser beam, which is incident through a glass tube 70 on a light receiving element 60 in a light receiving system R. In passing through the glass tube 70, the outgoing laser beam scatters at the tube portion with no liquid fuel by residual fuel deposing on the inner wall thereof, but travels as it is at the tube portion with liquid fuel. Depending on the resultant difference in beam intensity, the light receiving element 60 outputs a light reception signal, according to which an injection quantity arithmetic circuit 140 calculates a fuel injection quantity Q, and then a pulse width arithmetic circuit 150 calculates a pulse width τ and feeds it as pulse data to a supplementary valve drive circuit 160. The drive circuit 160 accordingly drives a fuel supplementary valve 90 such that the valve 90 jets liquid fuel in a fuel tank 100 out into a communicating passing 14 in the intervals between the injection timing of a fuel injection valve 120.