Abstract: A sensor assembly includes a fastener body extending from a fastener end to an opposite sensor end along an elongation direction. The sensor end is shaped to be inserted into a sensor port of an air dryer. A sensor substrate includes one or more conductive bodies protruding from the sensor substrate and one or more first conductive pathways coupled with the one or more conductive bodies. The sensor assembly also includes a sensor coupled with the sensor substrate and conductively coupled with the one or more conductive bodies by the one or more first conductive pathways. The sensor is configured to sense a humidity of air flowing through the air dryer. The one or more conductive bodies of the sensor substrate are positioned to engage one or more arcuate or annular conductive pathways in the air dryer in different rotational positions of the fastener body relative to the air dryer.

Abstract: A sensor assembly includes a fastener body extending from a fastener end to an opposite sensor end along an elongation direction. The sensor end is shaped to be inserted into a sensor port of an air dryer. A sensor substrate includes one or more conductive bodies protruding from the sensor substrate and one or more first conductive pathways coupled with the one or more conductive bodies. The sensor assembly also includes a sensor coupled with the sensor substrate and conductively coupled with the one or more conductive bodies by the one or more first conductive pathways. The sensor is configured to sense a humidity of air flowing through the air dryer. The one or more conductive bodies of the sensor substrate are positioned to engage one or more arcuate or annular conductive pathways in the air dryer in different rotational positions of the fastener body relative to the air dryer.

Abstract: A system for operating a locomotive parking brake includes a wheel brake, a coupling connected to the wheel brake, and means for applying force to the coupling. A sensor connected to the coupling measures a force applied to the coupling and generates a signal reflective of the force applied to the coupling. A method for operating a locomotive parking brake includes applying a force to a coupling connected to a wheel brake, measuring the force applied to the coupling, and comparing the force applied to the coupling to a first predetermined limit. The method further includes indicating that the force applied to the coupling is equal to or greater than the first predetermined limit.

Abstract: Apparatus and methods are disclosed for using membranes to reduce the relative humidity of a compressed air stream. Air dryers employing membranes consist of a permeable membrane capable of blocking the passage of nitrogen and oxygen molecules, but allowing water vapor molecules to pass through. A membrane filter may be adapted to receive process flow of contaminated air. A sweep chamber may be positioned adjacent to filtration media to pass a portion of dried air back into contact with a portion of the membrane. A flow metering device may be positioned downstream from the membrane filter to adjust a portion of the air process flow as sweep air. The amount of process flow air diverted as sweep air may be proportional to the pressure and flow of the process flow. In some applications, an optional minimum pressure valve may be employed downstream of the sweep chamber to maintain a minimum threshold pressure of process air flow.

Abstract: Apparatus and methods are disclosed for using membranes to reduce the relative humidity of a compressed air stream. Air dryers employing membranes consist of a permeable membrane capable of blocking the passage of nitrogen and oxygen molecules, but allowing water vapor molecules to pass through. A membrane filter may be adapted to receive process flow of contaminated air. A sweep chamber may be positioned adjacent to filtration media to pass a portion of dried air back into contact with a portion of the membrane. A flow metering device may be positioned downstream from the membrane filter to adjust a portion of the air process flow as sweep air. The amount of process flow air diverted as sweep air may be proportional to the pressure and flow of the process flow. In some applications, an optional minimum pressure valve may be employed downstream of the sweep chamber to maintain a minimum threshold pressure of process air flow.