Abstract: A capacitance transducer has a first hermetically sealed cavity adapted to deform in response to an applied force, such as pressure or acceleration, and a second hermetically sealed cavity adapted to resist deformation in response to such applied force. The cavities are formed between two doped silicon layers separated by a selectively etched electrically insulating spacer layer. Multiple medial electrically insulating cavity area spacer segments within the second cavity resist deformation thereof in response to the applied force to be measured. The capacitance transducer can be manufactured from doped silicon wafers using well developed silicon wafer processing techniques.

Abstract: A hot-wire mass air flow sensor includes integral, elongated silicon members with a silicon dioxide coating on which temperature sensitive resistors are deposited. The air flow sensor has an extremely low thermal conductivity material base on which is mounted one or more of the elongate silicon members. This structure maximizes the thermal impedance of the conductive path existing at the ends of the flow sensor resistors and minimizes sensor errors. A method for fabricating the air flow sensor is also provided.

Abstract: A technique for measuring the ion implant dosage involves method and apparatus for directing pulses of coherent radiation from a laser to the surface of a semiconductor that has been subjected to ion implant. The intensity of the third harmonic reflected from the semiconductor is determined and correlated to determine the ion dosage within the semiconductor.

Abstract: A method of determining if an internal combustion engine has been operated on a leaded fuel. The method has the following general steps. A misfueling detector is formed from a material which is capable of interacting with lead when exhaust gases containing lead are passed thereover. The interacting lead alters at least one measurable characteristic of the misfueling detector. The misfueling detector is placed in an exhaust system and exhaust gases from an internal combustion engine are allowed to pass thereover. The misfueling detector is removed from the exhaust system and the measurable characteristic thereof is measured to determine whether or not the misfueling detector had absorbed lead therein while located in the exhaust system of the internal combustion engine.