摘要 |
A fluid flow monitoring device consisting of a cylinder (4) having an inlet (1) and a plurality of outlets (16, 17, 18, 19); a piston (8) slideable within and in substantially fluid tight contact with the internal surface of the cylinder (4); biassing means (10) for biassing the piston (8) into a closed position which prevents fluid flowing to the outlets (16, 17, 18, 19) when the pressure difference in the fluid between the said inlet (1) and outlets (16, 17, 18, 19) is substantially zero but allows the piston (8) to move to different positions within the cylinder (4) to permit fluid flow through an increasing number of outlets (16, 17, 18, 19) when the pressure at the outlets increasingly falls below that at the inlet (1); and a detector (12, 13, 14) for detecting the position of the piston (8) within the cylinder (4) and thereby the occurrence of fluid flow through the device. |