A respiratory apparatus evaluates accuracy of a pressure sensor, such as when only a single pressure sensor is provided. The accuracy of the pressure sensor may be assessed based on pressure measurement obtained from the pressure sensor and a subordinate or secondary characteristic of the respiratory device such as altitude or atmospheric pressure. A controller or processor may calculate the altitude of the respiratory device based in part on the pressure measurement. In some embodiments, the assessment of the pressure sensor may involve an evaluation of the calculated altitude. In some cases, the assessment of the pressure sensor may involve determining an estimated pressure based on a calculated altitude, and comparing the pressure measurement obtained from the pressure sensor with the estimated pressure.

Multiple calibration results for calibrating a barometric pressure sensor based on data received from a device containing the sensor are determined and stored in a table. The table is updated based on rules regarding a relationship between each calibration result and a current calibration value. The calibration results are weighted and combined to determine a combined calibration result. The calibration value for calibrating the sensor is selected from the calibration results, the combined calibration results, or the current calibration value based on a selection criteria.

Determining when to calibrate a pressure sensor of a mobile device. Particular systems and methods determine values of a plurality of metrics, determine weights for the metric values, determine weighted metric values by applying the weights to the metric values, use the weighted metric values to determine if a pressure sensor of the mobile device should be calibrated using information associated with the first location, and calibrate the pressure sensor of the mobile device using the information associated with the first location if a determination is made that the pressure sensor of the mobile device should be calibrated using information associated with the first location.

A capacitive sensor includes a first conductive structure; a second conductive structure movable relative to the first conductive structure in response to an external force acting thereon, wherein the first and the second conductive structures form a first capacitor having a first capacitance that changes with a change in a distance between the first conductive structure and second conductive structure, wherein the first capacitance is representative of the external force; and a diagnostic circuit configured to detect a first leakage current in the capacitive sensor by measuring an first electrical parameter that is affected by the first leakage current and comparing the measured first electrical parameter to a first predetermined error threshold, wherein the diagnostic circuit is further configured to generate a first error signal in response to the measured first electrical parameter being greater than the first predetermined error threshold.

In one example in accordance with the present disclosure, an electronic device is described. The example electronic device includes an input device with a force sensor to measure a force applied to the input device. The example electronic device also includes a controller to receive a user selection of an object type for an object to be placed on a location of the input device. The controller is to determine a weight of the object in response to receiving the user selection. The controller is to also receive a force measurement from the force sensor in response to placement of the object on the input device. The controller is to calibrate the force sensor based on the object weight and the force measurement.

A controller configured for monitoring disturbances of a pressure sensor assembly includes at least two sensors. The at least two sensors are configured for measuring a pressure and wherein the at least two sensors have a sensor dependent measurement sensitivity for the pressure, and at least one of the sensors is sensitive for a disturbance with a sensor dependent disturbance sensitivity. A ratio of the measurement sensitivity and the disturbance sensitivity is different for the at least two sensors. The controller is configured for detecting the disturbance by comparing outputs of the at least two sensors.

The invention relates to equipment, devices and methods for testing a calibrated leak or passage of pressurized gas from a tire. In one example, a test plug including a calibrated cross section orifice and a predetermined gas flow rate is connected to a tire. The test plug applies a pressure opening the tire valve member to release gas from the tire through the test plug. In one example, a TPMS sensor and a TPMS measurement tool are used to measure the decrease of air pressure in the tire through the test plug and determine if the TPMS sensor is operating properly. In one example, a plurality of test plugs with different gas flow rates are provided. A method for testing the calibrated leak using the test plug is further disclosed.

An airflow sensor assembly for an air duct is provided. The airflow sensor assembly includes the air duct having an interior wall and an exterior wall, a high pressure pickup device, a low pressure pickup device, a pressure redirection device, and a pressure sensor. The pressure redirection device is fluidly coupled to the high pressure pickup device and the low pressure pickup device and includes a low inlet, a high inlet, and a common outlet. The pressure sensor is selectively fluidly coupled to the high pressure pickup device and the low pressure pickup device and includes a first inlet and a second inlet. The second inlet is fluidly coupled to the common outlet of the pressure redirection device.

A communication device, method and computer program product enable reduced polling of a barometric sensor, which reduces power consumption and sensor calibration drift. A controller of a communication device determines at least one of received signal strength and direction of respective broadcast signals from local network node(s) positioned within a building to provide a local coverage area. The controller determines a location of the communication device in relation to the local network nodes in response to determining the received signal strength and/or the direction of the respective broadcast signals. The controller determines current altitude data related to a current barometer reading of the barometric sensor. The controller compares the current and the historical altitude data associated with past reading(s) at the location. In response to determining that a difference between the historical and the current altitude data is greater than a threshold distance, the controller calibrates the barometric sensor.

Differential density system and method. A differential pressure transmitter measures a pressure difference between first and second pressure sensing locations. A reference vessel in fluid communication with the first pressure sensing location contains a reference fluid and a sample vessel in fluid communication with the second pressure sensing location contains a sample fluid. The reference fluid is in a first column above the first pressure sensing location and the sample fluid is in a second column above the second pressure sensing location. The second column is of substantially equal height as the first column. A value of total dissolved solids (TDS) in the sample fluid is determined based on the pressure difference.