A method for providing an enhanced estimate of reference barometric pressure. The method uses multiple, dissimilar pressure references, such as in airport weather stations, personal weather stations, and wireless terminals such as smartphones, in order to provide the enhanced estimate of reference barometric pressure. The method generates an enhanced estimate of reference barometric pressure based on a first estimate of reference barometric pressure from a first pressure reference network made up of airport weather stations, for example. The method also uses a second estimate of reference barometric pressure from a second pressure reference network made of up personal weather stations, for example, and a third estimate of reference barometric pressure, also from the second network. The first, second, and third estimates of reference barometric pressure are combined such that both measurement accuracy and timeliness are improved in the resulting, enhanced estimate.

A gas densimeter for monitoring a pressure or density of a gas in a gas chamber with a housing having a first housing chamber and a measuring chamber, a first coupling, via which the measuring chamber can be connected to the gas chamber, at least one reference bellows, which is connected directly or indirectly in particular to a transmission element, and at least one transmitting and/or monitoring unit, which is or can be operatively connected directly or indirectly to the transmission element. In this regard, the measuring chamber has a gas-permeable connection to the gas chamber via the first coupling and the reference bellows forms a reference chamber filled with a constant amount of a reference gas. A surface section covering the reference chamber is provided or reachable at least partially within the first housing chamber or measuring chamber as a measuring surface for the gas from the gas chamber.

A capacitive pressure sensor for an internal combustion engine is provided having a housing having a bottom surface, variable capacitor and circuitry. The variable capacitor is formed by a stationary electrode and an elastically bendable electrode. Pressure exerted on the bottom surface acts to bend the elastically bendable electrode. This bending alters the capacitance of the variable capacitor. The circuitry is configured to generate a signal based on the variable capacitance of the variable capacitor. This capacitance is representative of the pressure exerted on the bottom surface.

A detector that detects an alarm and/or fault condition with respect to a pressure of a medium is provided. The detector comprises a housing comprising an access tube configured to receive a medium and a bellows fixed to the housing comprising a cavity and a first contact surface. The detector also comprises an adjustment screw positioned within the cavity of the bellows, coupled to the housing via an insulation member, and comprising a second contact surface. The detector is further configured to detect a change in pressure of the medium based on whether the first contact surface and the first contact surface are in electrical communication.