The disclosure relates to a method for monitoring the operation of a pressure measuring cell of a capacitive pressure sensor, wherein the pressure measuring cell comprises a pressure-dependent measuring capacitor and a pressure-dependent reference capacitor and the pressure measuring value is obtained as a measuring signal from the capacitance values of the measuring capacitor and the reference capacitor, wherein the measuring signal is supplied to an evaluation unit in the form of an alternating square-wave signal, the pulse height of the signal depending on quotients of the capacitance values of the reference capacitor and the measuring capacitor and the period of the signal being determined by the capacitance value of the measuring capacitor such that, in the nominal pressure range of the pressure sensor, there is a fixed correlation between the pulse height and the period, wherein the pairs of values of pulse height and period (h1, d1), . . . , (hn, dn) are stored as nominal values in an adjustment procedure for determined pressure values p1, . . . , pn, and wherein, for the currently measured pressure value px, with the pair of actual values (h.sub.x-IST, d.sub.x-IST), the pair of nominal values (h.sub.x-SOLL, d.sub.x-SOLL) is determined, and if there is significant deviation between the pair of actual values and the pair of nominal values, an error signal is generated.

Fiber-optic equipment is often deployed in various locations, and performance of fiber-optic transmissions may be monitored as a gauge of equipment status to prevent costly and inconvenient communication outages. Events that damage equipment that eventually result in outage and may be desirable to address proactively, but the occurrence of such events may be difficult to detect only through equipment performance Presented herein are techniques for monitoring and maintaining fiber-optic equipment performance via enclosure sensors that measure physical properties within a fiber-optic equipment enclosure, such as temperature, pressure, light, motion, vibration, and moisture, which are often diagnostic and predictive of causes of eventual communication outages, such as temperature-induced cable loss (TICL), incomplete flash-testing during installation, exposure to hazardous environmental conditions, and tampering. An enclosure sensor package transmits the physical measurements to a monitoring station, and automatic determination of enclosure-related events may enable triaging and transmission of repair alerts to maintenance personnel.

The present invention provides a refrigerator comprising: a cabinet having a storage chamber; a door for opening or closing the storage chamber; a case in which an inlet through which air flows from the storage chamber and an outlet through which the air is discharged to the storage chamber are formed; an evaporator provided inside the case for exchanging heat with the air to supply cool air; and a differential pressure sensor provided inside the case.

Various embodiments include a method for checking a calibration of a pressure sensor comprising: moving a piston toward a TDC in successive cycles; while the piston moves toward TDC, closing an inlet valve thereby adjusting a setpoint value of a fluid pressure; measuring the fluid pressure with the pressure sensor arranged downstream of the outlet valve; applying a measurement current to the electromagnet when the inlet valve is closed; while the piston moves away from TDC, detecting an opening position of the inlet valve on the basis of a predetermined change with respect to time of the measurement current at which an opening movement of the inlet valve begins; over multiple pump cycles, changing the setpoint value of the fluid pressure by a predetermined difference; checking whether the change in opening position satisfies a predetermined correspondence criterion; and if the criterion is met, generating a fault signal.

Various embodiments include a method for monitoring a pressure sensor in a hydraulic system of a motor vehicle, the method comprising: actuating a valve of a pressure accumulator in the hydraulic system; detecting a behavior of the actuated valve in response to the actuation; determining a time offset of the actuated valve based on the detected behaviour; determining a measurement value of the pressure sensor; comparing the time offset of the valve with the determined measurement value; and checking a plausibility of the measurement value based on the comparison.

A readout circuit for use with a Wheatstone bridge sensor. At least some of the example embodiments are methods including: driving an excitation signal in parallel through a first set of sensor elements of a Wheatstone bridge sensor and refraining from driving the excitation signal through a second set of sensor elements of the Wheatstone bridge sensor; measuring response of the first set of sensor elements, the measuring response of the first set of sensor elements creates a first measurement; and then driving the excitation signal in parallel through the second set of sensor elements of the Wheatstone bridge and refraining from driving the excitation signal through the first set of sensor elements; and measuring response of the second set of sensor elements, the measuring response of the second set of sensor elements creates a second measurement.

A micromechanical piezoresistive pressure sensor includes a diaphragm configured to mechanically deform in response to an applied load, a sensor substrate located on the diaphragm, and a number of piezoresistive resistance devices located on the sensor substrate. The piezoresistive resistance devices are arranged in a first planar array defining a grid pattern having two or more rows, each row being aligned in a first direction. The piezoresistive resistance devices are configured to be electrically connected in a number of bridge circuits, whereby the piezoresistive resistance devices in each row is electrically connected in an associated bridge circuit. A method of using the micromechanical piezoresistive pressure sensor is also disclosed.

A pressure sensor is configured to monitor a first resistance value of a first resistor and a second resistance value of a second resistor. The first resistor and the second resistor are configured to be sensing elements of a sensing component of a pressure sensor. The pressure sensor is configured to determine, based on a difference between the first resistance value and the second resistance value satisfying a threshold, that a measurement from the sensing component is unreliable. The pressure sensor is configured to perform, based on determining that the measurement from the sensing component is unreliable, an action associated with the pressure sensor.

A sensor arrangement and a method of operating a sensor arrangement are disclosed. In an embodiment, a sensor arrangement includes a pressure sensor realized as a capacitive pressure sensor, a capacitance-to-digital converter, a test circuit and a switching circuit coupling the capacitance-to-digital converter and the test circuit to the pressure sensor.

The disclosure relates to a method for monitoring the operation of a pressure measuring cell of a capacitive pressure sensor, wherein the pressure measuring cell comprises a pressure-dependent measuring capacitor and a pressure-dependent reference capacitor and the pressure measuring value is obtained as a measuring signal from the capacitance values of the measuring capacitor and the reference capacitor, wherein the measuring signal is supplied to an evaluation unit in the form of an alternating square-wave signal, the pulse height of the signal depending on quotients of the capacitance values of the reference capacitor and the measuring capacitor and the period of the signal being determined by the capacitance value of the measuring capacitor such that, in the nominal pressure range of the pressure sensor, there is a fixed correlation between the pulse height and the period, wherein the pairs of values of pulse height and period (h1, d1), . . . , (hn, dn) are stored as nominal values in an adjustment procedure for determined pressure values p1, . . . , pn, and wherein, for the currently measured pressure value px, with the pair of actual values (h.sub.x-IST, d.sub.x-IST), the pair of nominal values (h.sub.x-SOLL, d.sub.x-SOLL) is determined, and if there is significant deviation between the pair of actual values and the pair of nominal values, an error signal is generated.