Abstract: A microwave method and apparatus for detecting the position of a piston of a pneumatic cylinder. While the piston is being moved by fluid pressure a microwave signal is applied to a cavity defined by the piston and interior of the cylinder and the reflected microwave signal is detected. The reflected microwave signal is processed to determine piston position.

Abstract: An apparatus for the analysis of gaseous media, the apparatus composed of a microwave transmitter; a microwave receiver; a measuring cell disposed between the transmitter and the receiver, composed of at least one Stark chamber, and having a gas inlet and a gas outlet; at least one Stark electrode disposed in, and electrically insulated from, the chamber; and a plurality of mutually spaced holders holding the electrode in a predetermined position in the chamber.

Abstract: A method for analyzing a gaseous medium with respect to a component having a characteristic absorption frequency spectral line, including the steps of generating microwave radiation at a selected frequency, generating a first Stark voltage selected to have a value such that a reference signal produced by subjecting the component to the microwave radiation and the first Stark voltage has a zero passage, resulting from the change in polarity between the spectral line and the Stark voltage lines, at a frequency coinciding with the characteristic absorption frequency spectral line, and regulating the microwave radiation frequency as a function of frequency shifts of the zero passage of the reference signal.