Patent ID: 8327692

Claim:
A device for measuring a concentration of fine particles contained in a fluid, comprising: a control volume body having an effective volume; an inlet path formed at an end of the control volume body, the inlet path configured to feed the fluid into the control volume body; an outlet path formed at another end of the control volume body, the outlet path configured to discharge the fluid from the control volume body; a plurality of measuring instruments provided at the inlet path and the outlet path, the plurality of measuring instruments configured to emit electrical signals when fine particles pass through the inlet path and the outlet path; and a computing machine configured for receiving the electrical signals transmitted from the measuring instruments and configured for computing the number and the concentration of fine particles contained in the control volume body; wherein the computing being performed by the steps of: counting numbers of the fine particles passing through the inlet and the outlet of the control volume body; calculating a difference in the numbers of fine particles measured; and dividing the difference calculated by the effective volume of the control volume body to give the concentration of the fine particles.