Systems and methods are described for determining whether liquid remains on a wafer surface following a scanning operation. A system embodiment includes, but is not limited to, a first system configured for positioning adjacent a transfer line coupled with a scanning nozzle to dispense fluid onto a wafer surface and to recover the fluid from the wafer surface, the first system configured to detect a gas/liquid transition of the fluid and determine a volume of liquid sample dispensed; a second system configured for positioning adjacent a second line downstream from the scanning nozzle, the second system configured to detect a gas/liquid transition of fluid flowing through the second line and determine a volume of liquid sample recovered from the wafer surface; and a controller configured to generate an alert if the volume of liquid sample recovered is not within a threshold amount compared to the volume of liquid sample dispensed.

Apparatus features a signal processor or signal processing module configured to: receive signaling containing information about a central air-core of an overflow pipe of a hydrocyclone where fluid flow is concentrated in an outer annular region of the overflow pipe that is against an inner wall of the overflow pipe during a normal operation of the hydrocyclone; and determine corresponding signaling containing information about a collapse of the central air-core of the overflow pipe of the hydrocyclone during an abnormal operation of the hydrocyclone, based upon the signaling received. The signaling contains information about a fluid flow rate of the fluid flow by detecting a change in the magnitude of a force and/or a moment on the probe.

In one embodiment, an electronic system comprises a display device to display data and processing logic coupled to the display device. The processing logic is configured to determine a duty cycle of at least one sensor for sensing flow of a product or particle through a product or particle line of an agricultural implement and to determine an amount of product or particles flowing through a line of the agricultural implement based on the duty cycle of the at least one sensor.

An example device includes a microfluidic channel and a movable element retained in the microfluidic channel to move from a first position to a second position by fluid flow through the microfluidic channel. The device includes a sensor to take a sensor reading to determine fluid flow through the microfluidic channel. The device includes a microfluidic pump to return the movable element from the second position to the first position. The device includes a controller to actuate the microfluidic pump and to determine a flow rate of the fluid flow through the microfluidic channel based on the sensor reading.

An example device includes a microfluidic channel and a movable element retained in the microfluidic channel to move from a first position to a second position by fluid flow through the microfluidic channel. The device includes a sensor to take a sensor reading to determine fluid flow through the microfluidic channel. The device includes a microfluidic pump to return the movable element from the second position to the first position. The device includes a controller to actuate the microfluidic pump and to determine a flow rate of the fluid flow through the microfluidic channel based on the sensor reading.

Gas and liquid velocities of fluid in a lift gas assisted well system are estimated by adding liquid and gas tracers downhole and monitoring their travel time over a known distance. Based on estimated velocities, a slip factor is obtained that represents relative velocities of the gas and liquid in the fluid. A flow regime of the fluid is identified based on the slip factor. The flow regime is optionally altered by adjusting one or more operational parameters of the well.

A system is disclosed for measuring fluid flow. The system may include a plurality of sensors and a computing device. The plurality of sensors may be positionable at different angles in a container of an offshore drilling rig to sense data about drilling fluid flow in the container. The computing device may be communicatively couplable to the plurality of sensors for receiving the data about the drilling fluid flow in the container and using the data to determine a calculated fluid flow rate compensating for movement of the offshore drilling rig.

A method for determining multi-phase flow properties of a fluid is disclosed. The method includes measuring a first time for a first ultrasonic signal to be emitted from a first transducer into the fluid, reflected off an inner surface of the pipeline, and received back at the first transducer. Measuring a second time for the first ultrasonic signal to be emitted from the first transducer into the fluid and received at a second transducer. Calculating, using the first time and the second time, at least one of: a liquid to gas ratio, a fluid density, a gas holdup, a liquid holdup, and a fluid velocity of the fluid flowing through the pipeline.

A microfluidic flow sensor may include a substrate having a microfluidic channel, an inert particle source to supply a fluid carrying an inert particle to the microfluidic channel and a sensor element along the microfluidic channel and spaced from the inert particle source. The sensor element outputs a signal based upon a sensed passage of the inert particle with respect to the sensor element. Portions of the microfluidic channel proximate the sensor element have a first size and wherein the inert particle provided by the inert particle source is to have a second size greater than one half the first size.

An apparatus for identifying and measuring volume fraction constituents of a fluid using time domain analysis and frequency domain analysis to identify individual volume fraction constituents within a pipe on a real time basis and to measure the volume of the individual volume fraction constituents flowing through the pipe on a real time basis.