Abstract: The invention relates to a high accuracy flowmeter for testing and calibrating flowmeters and the like, and more particularly to a positive displacement flowmeter which may include a cylinder (12), a piston (10) within the cylinder (12) which makes a clearance seal with the inside of the cylinder, an encoder (40) associated with the piston, and a control valve (V) for controlling the supply of a fluid flow (A1) to be measured. More generally, the flowmeter includes a channel for receiving a fluid flow so as to move the piston (10) within its enclosure (12); and a device (36, 38, 40) for detecting movement of the piston and generating electrical signals representative of the fluid flow to be measured. The movement of the piston is detected as a function of a known volume of the enclosure traversed by the piston, and a measured variable elapsed time over which the piston traverses the volume. Preferably, the flowmeter system includes a damping device (FIGS. 6A-6D) which may be mechanical, pneumatic, or fluidic.

Abstract: A positive displacement liquid flow meter uses two variable volume chambers 16,18 arranged in parallel, each with a reciprocable piston 24,26. While liquid from one chamber is being fed to the outlet 11, the other chamber is being charged with the liquid from the inlet 10. A sensing piston 32 in the outlet line 11 indicates when flow variation occurs and allows a feed back signal to be produced to produce the necessary alteration in movement of the piston from the chamber which is feeding the outlet line. Valves A, B, C, D are provided on either side of each chamber, so that when a chamber is feeding it is isolated from the liquid supply.

Abstract: A continuous volume measuring device for measuring the cumulative volume of a flowing fluid. The device includes a pair of coupled expandable chambers, and the fluid flow is directed into a first chamber to expand it while the second chamber is contracting and expelling liquid therefrom, the expansion of the first chamber being measured to determine the volume of fluid being received therein. When a predetermined volume of liquid is received, a valve means diverts the fluid flow to fill the second chamber, the expansion of which is similarly measured, and the first chamber is emptied. In the preferred embodiment, the chambers are precision syringes.

Abstract: A precision positive displacement flowmeter for providing an accurate measurement of fluid flow at one end of a fluid circuit, comprising a cylinder and piston arrangement constructed to receive and emit circuit fluid continually, and an indicator arranged to give an indication of such flow by monitoring piston movement.

Abstract: A flowmeter for measuring the throughput of a liquid from a source to a load, especially for gasoline, diesel oil, heating oil and the like, comprises at least two measuring cylinders having floating pistons and respective reversing elements which have two positions in which the reversing elements can be temporarily retained. A first reversing element is controlled by the first measuring cylinder and controls the reversal of flow of the liquid to the second measuring cylinder and vice versa. Means is provided for counting the strokes of each of the floating pistons to signal the quantity of displaced liquid.