A method and apparatus are provided for use with a pump. The method includes, (a) placing liquid in a tube coupled to the pump, (b) injecting an air bubble into the tube in a manner that does not increase pressure within the tube, and such that there is a predetermined volume of liquid between the air bubble and the pump, (c) using the pump to advance the air bubble along the tube to the bubble detector of the pump, (d) using the pump, assessing accuracy of the pump by automatically measuring the volume of liquid pumped to advance the air bubble to the bubble detector, and (e) using the pump to continue advancing the air bubble along the tube, past the bubble detector, and using the pump to measure a volume of the air bubble. Other applications are also described.

A method and apparatus are provided for use with a pump. The method includes, (a) placing liquid in a tube coupled to the pump, (b) injecting an air bubble into the tube in a manner that does not increase pressure within the tube, and such that there is a predetermined volume of liquid between the air bubble and the pump, (c) using the pump to advance the air bubble along the tube to the bubble detector of the pump, (d) using the pump, assessing accuracy of the pump by automatically measuring the volume of liquid pumped to advance the air bubble to the bubble detector, and (e) using the pump to continue advancing the air bubble along the tube, past the bubble detector, and using the pump to measure a volume of the air bubble. Other applications are also described.

An Automatic Pulse Tracer Velocimeter (APTV) including arc-type APTVs and cross-type APTVs along with a field station and a master station capable of wireless communication with a remote computing devices. The APTV measures flow velocity in a flowable medium by injecting a small amount of a conductive tracer solution into a water column. Following injection, a plurality of wire detector pairs positioned downstream of the injection point are programmed to continuously make conductivity measurements at pre-determined time intervals. A tracer curve of the conductivity measurements over time is created and used to obtain velocity measurements.

A droplet of fluid having a predetermined drop weight is ejected from a microfluidic channel. Electrical signals are received from a sensor in the microfluidic channel, wherein the electrical signals vary in response to the ejection of the droplet of fluid. The electrical signals of the sensor are calibrated to a rate of flow of fluid through the microfluidic channel based on a number of droplets ejected and the predetermined drop weight of each droplet.

A droplet of fluid having a predetermined drop weight is ejected from a microfluidic channel. Electrical signals are received from a sensor in the microfluidic channel, wherein the electrical signals vary in response to the ejection of the droplet of fluid. The electrical signals of the sensor are calibrated to a rate of flow of fluid through the microfluidic channel based on a number of droplets ejected and the predetermined drop weight of each droplet.

Methods of and devices for testing medical pumps via tracking induced bubble trajectories within a fluid flow conduit comprising a valve and methods of synchronized corrections of flow data estimates.

A fluid conductivity sensor (FCS) system for determining a water void fraction in a fluid mixture flows comprises a duct containing the fluid mixture flows; a dielectric window system operatively connected to the duct, wherein the dielectric window system comprises a first dielectric window built-into a first surface of a wall of the duct and a second dielectric window built-into a second surface of the wall aligned and opposite to the first surface; a split-toroidal loop-gap resonator (split-TLGR) system operatively connected to the dielectric window system and the duct, wherein the split-TLGR system comprises a first split-TLGR built-into the first dielectric window and a second split-TLGR built-into the second dielectric window; and a vector network analyzer (VNA) operatively connected to the split-TLGR system and configured to measure the fluid conductivity, wherein the water void fraction is derived from the fluid conductivity.