Abstract: A fluid meter comprises at least three sensors each having an output dependent on a respective characteristic of the fluid to be monitored, circuitry to combine the outputs of two of the sensors to provide a measurement of mass flowrate of the fluid, and to combine the outputs of the three sensors to provide an error signal which can be used to recalibrate the measurement.

Abstract: A fluid leak detector has a body with a chamber provided with a fluid inlet and outlet. A valve is disposed between the inlet and outlet and the valve closure member is connected to a diaphragm. Fluid in the chamber applies pressure on the diaphragm and the detector includes means which allow the valve to be open at a pressure greater than a predetermined value and cause the valve to close at pressures below that value, which may be due to a fluid leak. The detector has a safety lock-off mechanism which locks the valve once it has closed and which must be reset to allow the valve to open when fluid pressure has been restored. The detector also provides a visual indication of fluid leaks. A fluid supply installation incorporating the fluid leak detector will shut down the fluid supply if a leak is detected.

Abstract: A fluidic-oscillator type flowmeter has an inlet nozzle (1) leading into a chamber (2) with diverging side walls (3a, 3b). A splitter (8) has a blunt end opposite the inlet nozzle and defines outlet paths (4a, 4b) which lead from the chamber. The shape and position of the splitter are such that oscillating flow is encouraged across its face. Feedback channels (5a, 5b) lead from the side walls back to control ports (7a, 7b) which open into the chamber. The relative position of the splitter and feedback channel entrances is such that the downstream corners of the entrances to the feedback channels lie in the oscillating path of the edge of the flow which separates from the face of the splitter when the meter is in use.