A watertight electrical compartment for use in an irrigation device can include a compartment body with a chamber, a sealing section mounted with one or more sealing rings, and external threads. A sealing cap mate with the sealing section and/or the sealing rings to seal the chamber. A cap retainer can be advanced over at least a portion of the sealing cap and can have internal threads to be screwed onto the external threads of the compartment body. The cap retainer can also have a stopping feature to keep the sealing cap in its sealed position. The watertight electrical compartment can be used in a wireless flow sensor assembly, a battery operated irrigation controller, and/or a battery-operated central controller device, to provide irrigation control, and/or sensor information, without the need for AC power.

A turbine wheel used in a turbine flow meter includes a hub configured to be freely rotatably fixed in position inside a fluid pipe section. A first cylindrical rim is centered about the hub and the longitudinal axis and spaced a distance apart from the hub. A first vane set extends outwardly from the hub to the first cylindrical rim, wherein a root of each vane of the first vane set is attached to the hub and a tip of each vane of the first vane set is attached to the first cylindrical rim. The first vane set may consist of one or two individual vanes. An external vane set may extend outwardly from the first cylindrical rim, wherein a root of each vane is attached to the first cylindrical rim and a tip of each vane is not attached to any cylindrical rim.

A turbine wheel used in a turbine flow meter includes a hub configured to be freely rotatably fixed in position inside a fluid pipe section. A first cylindrical rim is centered about the hub and the longitudinal axis and spaced a distance apart from the hub. A first vane set extends outwardly from the hub to the first cylindrical rim, wherein a root of each vane of the first vane set is attached to the hub and a tip of each vane of the first vane set is attached to the first cylindrical rim. The first vane set may consist of one or two individual vanes. An external vane set may extend outwardly from the first cylindrical rim, wherein a root of each vane is attached to the first cylindrical rim and a tip of each vane is not attached to any cylindrical rim.

An optical flow rate sensor system for a sprayer includes an optical sensor, an optical sensor window within a display housing, a projectile within a drum housing, and vortexing geometry upstream of the projectile. The optical sensor is located adjacent to the optical sensor window. The projectile includes a first section having a first optical absorption value and a second section having a second optical absorption value that is lower than the first optical absorption value. The projectile is configured to revolve around an axis of the drum housing.

A fan, in particular axial fan and preferably backward-curved radial fan, having an impeller equipped with blades, an electric motor for rotating the impeller and a device for determining the airflow when the impeller is rotating. The device for determining the airflow includes a volume flow measuring wheel arranged in the air flow, which is arranged upstream of the impeller on the inflow side. The air volume flow is calculated or derived from the rotational speed of the volume flow measuring wheel.

A dosing device for dispensing a predetermined amount of liquid, in particular a predetermined amount of water, has a housing with a liquid inlet, a liquid outlet, and a flow channel therebetween. A valve element in the flow path can be opened and closed. A measuring device measures the flow rate through the flow channel in the direction of the liquid outlet. A controller has an operating unit or is coupled to an operating unit for signal transmission. The dosing device is actuatable by the operating unit. The controller is further coupled in terms of control technology to the valve element and to the measuring device, the controller holding the valve element in an open position or moving it to an open position when the dosing device is actuated.

Described is apparatus housing an instrumented device and an inner tube providing a fluid flow path therethrough. A strain gauge is on the outer surface of the inner tube. Bulkhead(s) transfers forces from an external housing to the inner tube to be detected by the strain gauge. Flow sensors measure fluid flow velocity and/or fluid flow volume rate. Pressure sensors sense pressure differential between an inlet side and an outlet side of the apparatus. Sensors provide for measurement of RPM, WOB, azimuth and rate of penetration. Communication means (such as a Wi Fi transceiver) and/or GPS device can communicate through EM transparent windows. The apparatus is used aboveground axially in-line in a drill string.

A passive microscopic flow sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fiber. The three-dimensional microscopic optical structure includes a post attached off-center to and extending longitudinally from the cleaved tip of the optical fiber. A rotor of the three-dimensional microscopic optical structure is received for rotation on the post. The rotor has more than one blade. Each blade has a reflective undersurface that reflects a light signal back through the optical fiber when center aligned with the optical fiber, the blades of the rotor shaped to rotate at a rate related to a flow rate.

An aspect of the present invention pertains to a method for determining the volumetric flow rate of a compressible fluid flow flowing through a volume flowmeter having a flow inlet, a wheel downstream of the flow inlet and a constriction downstream of the flow inlet and upstream of the wheel, the compressible fluid flowing through the flow inlet and actuating the wheel. The method comprises measuring the rotational speed of the wheel and determining the permanent pressure loss across the wheel based on the measured rotational speed. The method further comprises measuring the fluid pressure of the compressible fluid flow at the flow inlet and determining whether the compressible fluid flow in the volume flowmeter is in the subsonic or in the supersonic regime based on the determined permanent pressure loss and the measured fluid pressure. The method also comprises measuring the fluid temperature of the compressible fluid flow at the flow inlet and determining the volumetric flow rate of the compressible fluid flow based on the determined permanent pressure loss, the measured fluid pressure, the regime of the compressible fluid flow and the measured fluid temperature. Other aspects of the present invention pertain to volume flowmeter for determining the volumetric flow rate of a compressible fluid flow, a data processing device for controlling a volume flowmeter, a computer program for the controller and a computer-readable medium having stored thereon the computer program.

An aspect of the present invention pertains to a method for determining the volumetric flow rate of a compressible fluid flow flowing through a volume flowmeter having a flow inlet, a wheel downstream of the flow inlet and a constriction downstream of the flow inlet and upstream of the wheel, the compressible fluid flowing through the flow inlet and actuating the wheel. The method comprises measuring the rotational speed of the wheel and determining the permanent pressure loss across the wheel based on the measured rotational speed. The method further comprises measuring the fluid pressure of the compressible fluid flow at the flow inlet and determining whether the compressible fluid flow in the volume flowmeter is in the subsonic or in the supersonic regime based on the determined permanent pressure loss and the measured fluid pressure. The method also comprises measuring the fluid temperature of the compressible fluid flow at the flow inlet and determining the volumetric flow rate of the compressible fluid flow based on the determined permanent pressure loss, the measured fluid pressure, the regime of the compressible fluid flow and the measured fluid temperature. Other aspects of the present invention pertain to volume flowmeter for determining the volumetric flow rate of a compressible fluid flow, a data processing device for controlling a volume flowmeter, a computer program for the controller and a computer-readable medium having stored thereon the computer program.