Abstract: A mass air flow sensor housing for reducing backflow includes a U-shaped air flow path having an elliptical inlet and an outlet. A mass air flow sensor is positioned in the U-shaped air flow path. A converging ellipse inlet to the U-shaped air flow path reduces turbulent air flow. A deflecting wedge positioned upstream of the outlet creates a low pressure area adjacent the outlet for promoting air flow through the U-shaped bypass.

Abstract: A housing structure for mass air flow sensors includes an auxiliary passage way, internal to the structure, that diverts a portion of the main air flow towards sensing elements. The sensing elements are shielded from the main air flow, so the contaminants separate from the diverted air at the point of diversion and continue downstream in the main air flow. The decontaminated, diverted air passes over the sensing elements and out of the housing structure through two exit openings located in the rear of the structure. The housing structure, by locating the sensing elements within itself, away from the main air flow, and locating exit openings for the diverted air behind a blocking wall, is also able to eliminate the effect of backflow air over the mass air flow sensing elements.

Abstract: A method and apparatus for calibrating a mass air flow sensor in which the sensing elements of the sensor are subjected to an oscillating mass air flow summed with an offset mass air flow to produce the summed mass air flow. The output waveform of the mass air flow in response to the summed mass air flow is displayed on a display having a desired waveform superimposed thereon. Selected resistors in the sensor's electronic circuit are then trimmed to conform the waveform output by the mass air flow sensor with the superimposed desired waveform.

Abstract: A method and apparatus for calibrating a mass air flow sensor in which the sensing elements of the sensor are subjected to an oscillating mass air flow summed with an offset mass air flow to produce the summed mass air flow. The output waveform of the mass air flow in response to the summed mass air flow is displayed on a display having a desired waveform superimposed thereon. Selected resistors in the sensor's electronic circuit are then trimmed to conform the waveform output by the mass air flow sensor with the superimposed desired waveform.

Abstract: A mass air flow sensor arrangement that has a mass air flow sensor fixedly mounted on a sensor mount which is connected to the low pressure region of a downstream venturi. The sensor mount has an isolation air flow conduit in which is received the sensing head of the mass air flow sensor. The air flow conduit of the sensor mount is disposed in the air filter housing of an internal combustion air intake system. The air flow conduit is located in a low flow region of the air filter housing and has its outlet end connected to the low pressure region of the venturi located downstream of the air filter housing. The venturi may be connected directly to the outlet port of the air filter housing or may be located further downstream.

Abstract: A remote mount mass air flow sensor that has a mass air flow sensor fixedly mounted on a sensor mount. The sensor mount has an isolation air flow conduit in which is received the sensing head of the mass air flow sensor. The remote mount mass air flow sensor may be mounted directly on a sensor housing forming part of the main air duct of an air intake system of an internal combustion engine.

Abstract: A housing structure for reducing back air flow to the mass air flow sensor of an internal combustion engine. The housing structure consists of a housing defining a main air flow passage therethrough. A bypass passage is provided in the housing parallel to a longitudinal axis of the main air flow passage which receives therein the sensing head of the mass air flow sensor. A recovery chamber is connected to the bypass passage and is enclosed by an internal structure. The internal structure forms a pair of venturies with the sidewalls of the housing which induces an air flow through the bypass passage and the recovery chamber. A calibrated aperture is provided through the internal structure connecting the recovery chamber to the main air flow passage downstream of the bypass passage. The calibrated aperture reduces the air flow through the bypass passage during a back air flow.