Abstract: A fluid flow sensing device can include a tapered fluid flow channel formed into a main channel defining a fluid flow tube as an alternate fluid flow path. A tapered fluid flow channel can bypass some fluid flow from the main fluid flow channel into the alternate fluid flow path and a flow sensor disposed within the alternate fluid flow path. The tapered flow channel is tapered in a direction of fluid flow toward the flow sensor to thereby reduce flow eddies and enable optimal sensing performance by fluid flow sensor. An upstream fluid flow channel and a downstream fluid flow channel can be molded into the main fluid flow channel, especially bypassed in the fluid flow path of the main fluid flow channel. A fluid flow sensor can be placed between the upstream fluid flow channel and the downstream fluid flow channel for measuring fluid flow rate the channel.

Abstract: The present disclosure relates generally to flow sensors, and more particularly, to devices and methods for providing a pressure drop through a flow sensor at a given flow rate. In one illustrative embodiment, a sensor assembly includes a housing with a first flow port and a second flow port. The housing may define a fluid channel extending between the first flow port and the second flow port, with a sensor positioned in the housing and exposed to the fluid channel. The illustrative sensor may be configured to sense a measure related to the flow rate of a fluid flowing through the fluid channel. A flow restrictor may be situated in and integrally molded with at least one of the first flow port and the second flow port. The flow restrictor may be configured to accurately provide a pressure drop through the flow sensor at a given flow rate.

Abstract: The present disclosure relates generally to sensors, and more particularly, to methods and devices for reducing moisture, dust, particulate matter, and/or other contaminates entering a sensor. In one illustrative embodiment, a sensor assembly includes a housing with an inlet flow port and an outlet flow port. The housing defines a fluid channel extending between the inlet flow port and the outlet flow port, with a sensor positioned in the housing and exposed to the fluid channel. The illustrative sensor is configured to sense a measure related to the flow rate of a fluid flowing through the fluid channel. A hydrophobic filter may be situated in the fluid channel, sometimes upstream of the sensor. When so configured, and during operation of the sensor assembly, a fluid may pass through the inlet flow port, through the hydrophobic filter, across the sensor, and through the outlet flow port. The hydrophobic filter may be configured to reduce the moisture entering the fluid channel of the sensor.

Abstract: The present disclosure relates generally to flow sensors, and more particularly, to methods and devices for reducing variations in fluid flow across the flow sensor for increased accuracy and/or reliability. In one illustrative embodiment, a flow sensor assembly includes a housing with an inlet flow port and an outlet flow port. The housing defines a fluid channel extending between the inlet flow port and the outlet flow port, with a flow sensor positioned in the housing and exposed to the fluid channel. The flow sensor is configured to sense a measure related to the flow rate of a fluid flowing through the fluid channel. A porous insert is situated in the fluid channel, sometimes upstream of the flow sensor. When so configured, and during operation of the flow sensor assembly, a fluid may pass through the inlet flow port, through the porous insert, across the flow sensor, and through the outlet flow port.

Abstract: A corrosion resistant flow sensor apparatus includes a flow sensor including a micromachinable substrate mounted on a package substrate that includes electrically conductive traces and substrate bond pads. The flow sensor includes a MEMS sensing structure for sensing a mass flow parameter and sensor bond pads coupled to the sensing structure. The sensor bond pads include a top metal layer on a metal diffusion barrier layer including a metal diffusion barrier layer sidewall. Bond wires couple the sensor bond pads to the substrate bond pads. A housing including sides and a top portion is around the flow sensor and includes a flow channel having an inlet and an outlet. A multi-layer corrosion protection coating includes a nm scale adhesion layer and a self assembled monolayer (SAM) is on the adhesion layer. The protection coating covers the sensor bond pads including the metal diffusion barrier layer sidewall.

Abstract: A fluid flow sensing device can include a tapered fluid flow channel formed into a main channel defining a fluid flow tube as an alternate fluid flow path. A tapered fluid flow channel can bypass some fluid flow from the main fluid flow channel into said alternate fluid flow path and a flow sensor disposed within said alternate fluid flow path. The tapered flow channel is tapered in a direction of fluid flow toward said flow sensor to thereby reduce flow eddies and enable optimal sensing performance by fluid flow sensor. An upstream fluid flow channel and a downstream fluid flow channel can be molded into the main fluid flow channel, especially bypassed in the fluid flow path of the main fluid flow channel. A fluid flow sensor can be placed between the upstream fluid flow channel and the downstream fluid flow channel for measuring fluid flow rate the channel.

Abstract: A high mass-flow sensing apparatus and method of forming the same, comprising a flow tube bypassed in a flow path defined by a flow channel, through which a fluid flows. A flow sensor can be disposed in the flow tube for measuring a flow rate of the fluid in the flow channel. A set of narrow rectangular flow restrictors can be molded into the flow tube and adjacent to the flow sensor. Each flow restrictor can include several rectangular cutouts that are molded into upstream and/or downstream portions of the flow tube in order to limit the flow rate of the fluid across the flow sensor. The flow restrictors can laminarize the flow rate of the fluid in the flow tube and thereby reduce flow turbulence and lead to optimal sensing performance of the flow sensor.

Abstract: A sensor apparatus includes a heating element comprising an upstream side and a downstream side. A first heat sensing set is generally configured adjacent to the upstream side of the heating element and comprises a first sensing element and a second sensing element, the first and second sensing elements configured in a serpentine, interdigitated pattern. A second heat sensing set can be configured adjacent to the downstream side of the heating element and comprises a third sensing element and a fourth sensing element, the third and fourth sensing elements configured in a serpentine, interdigitated pattern.

Abstract: A fluid velocity sensor includes a sensor die for detecting a fluid property of a fluid flowing through a low resistance flow channel defined by a flow channel wall. One or more tap can be oriented facing into a direction of a flow stream of a fluid flowing through a flow channel defined by a channel wall, wherein the tap(s) leads to the low resistance flow channel, which directs the flow to the sensor die. At least one or more other taps can be located to face perpendicular to the direction of flow, such that the fluid after passing over the sensor die continues on a low resistance path to the other tap(s) facing perpendicular to the direction of flow in order to determine a velocity pressure based on a difference between pressures. The fluid velocity sensor can be arranged in a uni-directional or bidirectional fluid flow configuration.

Abstract: A thermal liquid flow sensor and method of forming same. The sensor has a substrate and one or more sensing elements, disposed on the substrate, for sensing a property of a liquid. The liquid flow sensor, which can be for example a microsensor having a microbrick® structure, has a hydrophilic layer which is disposed on the substrate and covers the sensing element(s). The hydrophilic layer is preferably formed from a spin on glass material, such as for example a silicate or phosphosilicate. A silicon nitride layer can be disposed on the sensing element(s) and interpose the substrate and the hydrophilic layer. The silicon nitride layer can be oxidized, for example, by means of plasma oxidation or oxygen ion implantation so to form the hydrophilic layer thereon. A variety of other hydrophilic compounds can be utilized to form the hydrophilic layer such as, gold, palladium and diamond like carbon.

Abstract: A system and method for heating a fluid include a base and a cover, and a flexible heating element maintained between the base and the cover. A wall plate can be provided to which the flexible heating element is connected to create a sealed fluidic flow path encased between the base and the cover, which provides a geometry that creates at least one air pocket for thermal isolation. A fluid can then flow through the fluidic flow path in order to be heated by the flexible heating element, thereby permitting the fluid to be heated to a desired temperature within a particular timeframe. The flexible heater can be formed from, for example, copper. The fluid is mixed in the fluidic flow path to ensure a uniform temperature of the liquid at an exit of the fluidic flow path.

Abstract: A humidity sensing apparatus and method include a substrate and a MEMS structure, wherein the MEMS structure is supported by the substrate. The MEMS structure comprises a humidity-sensitive material in association with a movable member such that when the humidity-sensitive material changes with humidity, the MEMS structure moves the movable member, thereby providing an indication of humidity based on a stress within the MEMS structure.

Abstract: A humidity sensing apparatus and method includes a humidity sensor capable of measuring relative humidity and a heater located about and proximate to the humidity sensor wherein a portion of the heater comprises a material that permits a diffusion of air through the material of the heater. A sensing area is generally formed between the heater and the humidity sensor, wherein the heater provides a heated environment within the sensing area in order to evaporate water droplets that form within the sensing area and reduce relative humidity to a measurable level and measure supersaturated air within the sensing area.

Abstract: Sensor systems and methods are disclosed herein. A relative humidity sensor is generally associated one or more porous heating elements. A porous resistive material surrounds the relative humidity sensor. Additionally, one or more flat heating elements can be bonded to a base of the relative humidity sensor to conduct heat and insure uniform heating about the relative humidity sensor. The porous heating elements can be configured to permit humid air to pass through the porous heating elements. Also, the porous heating element(s) can be assembled slightly offset from a surface of the relative humidity sensor so that air that is saturated with water vapor passes through and is heated by the porous heating element in order to evaporate water droplets associated with the water vapor and thereby reduce relative humidity to a measurable level. The porous resistive material can be configured from a material such as, for example, tantalum or nichrome.

Abstract: Sensor systems and methods are disclosed herein. A relative humidity sensor can be associated with one or more ceramic heating elements configured from a porous material. In general, a perimeter of the relative humidity sensor is surrounded with a relatively conductive material. A resistive material surrounds one or more of the ceramic heating elements, such that air that is saturated with water vapor passes through the porous material of the ceramic heating element(s). Water vapor can therefore be heated by the ceramic heating element(s) in order to evaporate water droplets associated with the water vapor and thereby reduce relative humidity to a measurable level. The porous material of the ceramic heating element(s) can be provided via a plurality of laser drilled holes to create such porosity.

Abstract: Sensor systems and methods are disclosed herein. A relative humidity sensor can be associated with one or more heating elements, wherein a perimeter of the relative humidity sensor is surrounded with a relatively conductive material. A thin substrate material can surround and laminate the heating element, such that the heating element is porous to permit humid air to pass through the heating element and wherein the at the heating element is assembled slightly offset from a surface of the relative humidity sensor. Air that is saturated with water vapor can then pass through and be heated by the heating element in order to evaporate water droplets associated with the water vapor to thereby reduce relative humidity to a measurable level.

Abstract: A high mass flow sensor device having a flow restrictor formed by a body having a generally cylindrical shape with an upstream end and a downstream end separated by a center portion having pressure taps proximate the junction of the ends with the center portion. Flow passes from upstream to downstream. The upstream end has a decreasing tapering inner surface for contact with the flow and the downstream end having an increasing tapering inner surface for contact with the flow. A center portion has radial and axial restrictor elements positioned forming axial openings in the path of flow through the center portion. The restrictor elements having tapered leading edges. One opening is formed by a central tube having a predetermined diameter and the remaining openings are radially extending members supporting the central tube, each of the radially extending members having substantially the same cross-sectional area as the central tube.

Abstract: Methods and systems for preventing degradation of a sensor exposed to a harsh fluid, such as one that might corrode or be exposed to radioactive contaminants, live pathogens, freezing temperatures, overheating, particle deposition or condensable vapors is disclosed. An auxiliary purge stream of comparatively clean fluid or purge fluid is utilized, which flows past the sensor in opposition to the harsh fluid, thereby preventing the harsh fluid from contacting and degrading the sensor. The clean fluid itself may comprise a purge gas, such as clean, dry air, or a liquid that is compatible with the composition of the harsh fluid. The flow and pressure of the clean fluid can be adjusted utilizing one or more supply regulator valves.

Abstract: Methods and systems for preventing degradation of a sensor exposed to a harsh fluid, such as one that might corrode or be exposed to radioactive contaminants, live pathogens, freezing temperatures, overheating, particle deposition or condensable vapors is disclosed. An auxiliary purge stream of comparatively clean fluid or purge fluid is utilized, which flows past the sensor in opposition to the harsh fluid, thereby preventing the harsh fluid from contacting and degrading the sensor. The clean fluid itself may comprise a purge gas, such as clean, dry air, or a liquid that is compatible with the composition of the harsh fluid. The flow and pressure of the clean fluid can be adjusted utilizing one or more supply regulator valves.