The present disclosure is directed toward a method for measuring a seal gap between a closing member and a fixed member. The method includes applying a liquid agent having transferable properties along one or more regions of a stamping member to form one or more base marks. The stamping member is one of the closing member or the fixed member. The method further includes engaging the closing member with the fixed member, disengaging the closing member from the fixed member, and assessing a seal gap between the closing member and the fixed member based on one or more remnant patterns formed on an imprinted member. The imprinted member is the other one of the closing member and the fixed member, and the remnant patterns are formed by the transfer of the liquid agent from the base marks.

A gas gauge proximity sensor comprising a measurement gas flow channel having an optical pressure sensor for comparing a pressure of the first gas flow and a reference pressure; the optical pressure sensor comprising a first optical cavity fluidly connected to the measurement channel and a second optical cavity fluidly connected to the reference pressure, with the optical cavities being configured to receive electromagnetic radiation and output reflected electromagnetic radiation, the optical pressure sensor further being configured to combine the reflected electromagnetic radiation from the first optical cavity with the reflected electromagnetic radiation from the second optical cavity and determine, based on the combined electromagnetic radiation, a pressure difference between the pressure of the first gas flow and the reference pressure and determine, based on the pressure difference, a distance between the measurement outlet and the measurement object.

A gas gauge proximity sensor comprising a measurement gas flow channel having an optical pressure sensor for comparing a pressure of the first gas flow and a reference pressure; the optical pressure sensor comprising a first optical cavity fluidly connected to the measurement channel and a second optical cavity fluidly connected to the reference pressure, with the optical cavities being configured to receive electromagnetic radiation and output reflected electromagnetic radiation, the optical pressure sensor further being configured to combine the reflected electromagnetic radiation from the first optical cavity with the reflected electromagnetic radiation from the second optical cavity and determine, based on the combined electromagnetic radiation, a pressure difference between the pressure of the first gas flow and the reference pressure and determine, based on the pressure difference, a distance between the measurement outlet and the measurement object.

A measuring device (10) for measuring the space remaining after a side crash has a pneumatic piston rod cylinder (20) with a cylinder (22), and a piston rod (24) that can move relative to the cylinder (22). A measuring unit (40) measures the movement (26) of the piston rod (24) relative to the cylinder (22), and a base part (12) positions the piston rod cylinder (20). The piston rod cylinder (20) can be connected to a pressure vessel (70) to permit the piston rod (24) to move out when a fluid is applied to the piston rod cylinder (20).

A measuring device (10) for measuring the space remaining after a side crash has a pneumatic piston rod cylinder (20) with a cylinder (22), and a piston rod (24) that can move relative to the cylinder (22). A measuring unit (40) measures the movement (26) of the piston rod (24) relative to the cylinder (22), and a base part (12) positions the piston rod cylinder (20). The piston rod cylinder (20) can be connected to a pressure vessel (70) to permit the piston rod (24) to move out when a fluid is applied to the piston rod cylinder (20).

A device and method of precise distance measurement of a transmission line to any object below it is disclosed, along with a network of such devices. The technique employs ultrasonic or laser sensor technology to measure the distance to the nearest object, be it vegetation or a crossing conductor below, and reports that distance wirelessly to the system operator or transmission asset owner. The ultrasonic measurement package may be part of a Transmission Line Security Monitor, which mounts to a transmission line conductor and is powered by the transmission line, transmitting the data by radio links. The technology is equally applicable to encroachment of objects from the side (for example, other transmission lines), as well as to other electrical lines, such as distribution lines, or to other sensing. A built-in transceiver allows the device to communicate with other devices and forward alerts from these devices in a daisy-chain fashion to the intended recipient.

A device and method of precise distance measurement of a transmission line to any object below it is disclosed, along with a network of such devices. The technique employs ultrasonic or laser sensor technology to measure the distance to the nearest object, be it vegetation or a crossing conductor below, and reports that distance wirelessly to the system operator or transmission asset owner. The ultrasonic measurement package may be part of a Transmission Line Security Monitor, which mounts to a transmission line conductor and is powered by the transmission line, transmitting the data by radio links. The technology is equally applicable to encroachment of objects from the side (for example, other transmission lines), as well as to other electrical lines, such as distribution lines, or to other sensing. A built-in transceiver allows the device to communicate with other devices and forward alerts from these devices in a daisy-chain fashion to the intended recipient.

An apparatus, such as a lithographic apparatus, has a metrology frame that has a reference frame mounted thereon that includes a reference surface. A gas gauge is movable relative to the reference frame, metrology frame, and a measured surface. A reference nozzle in the gas gauge provides gas to the reference surface and a measurement nozzle provides gas to the measured surface. A microelectromechanical (MEM) sensor may be used with the gas gauge to sense a difference in backpressure from each of the reference nozzle and the measurement nozzle. Optionally, multiple gas gauges are positioned in an array, which may extend in a direction that is substantially parallel to a plane of the measured surface. The gauges may be fluidly connected to a reference nozzle of the gas gauge. A channel may distribute gas across the array.

An apparatus, such as a lithographic apparatus, has a metrology frame that has a reference frame mounted thereon that includes a reference surface. A gas gauge is movable relative to the reference frame, metrology frame, and a measured surface. A reference nozzle in the gas gauge provides gas to the reference surface and a measurement nozzle provides gas to the measured surface. A microelectromechanical (MEM) sensor may be used with the gas gauge to sense a difference in backpressure from each of the reference nozzle and the measurement nozzle. Optionally, multiple gas gauges are positioned in an array, which may extend in a direction that is substantially parallel to a plane of the measured surface. The gauges may be fluidly connected to a reference nozzle of the gas gauge. A channel may distribute gas across the array.

A detection device for the seating detection of an object on a clamping device includes a measuring chamber with an inflow opening to supply a detection fluid from a pressure source, at least one outflow opening to discharge the detection fluid to a pressure sink and with at least one detection opening, which can be closed at least partially by the object abutting on the clamping device. An inflow resistance limits an inflow of the detection fluid via the inflow opening, at least one outflow resistance limits an outflow of the detection fluid via the at least one outflow opening and a pressure sensor determines a pressure of the detection fluid in the measuring chamber.