Abstract: Methods and apparatus for improving performance of a sensor having a sensor proof mass elastically suspended at an initial equilibrium position by a suspension force, provide a tunable force opposing that suspension force and preset the proof mass with that tunable force to a second equilibrium position less stable than the initial equilibrium position. The sensor is then operated from that preset second equilibrium position of the proof mass short of instability. The spring constant of the elastic suspension may be continually monitored, and such continually monitored spring constant may be continually adjusted to maintain the sensor at a substantially constant sensitivity during its operation.

Abstract: A method of selectively sensing the quantity of methane gas in an oxygen containing gas stream, which method, as taught in one of its preferred embodiment, includes the step of providing a platinum catalyst (12) and a palladium catalyst (14). The platinum and the palladium catalysts are electrically interconnected (16--16) so as to obtain an electrical output reading (24) therefrom. The electrically interconnected catalysts are heated to a temperature in a range of 350.degree.-450.degree. C. whereby a reference electrical output reading is obtained therefrom. A gas stream containing suspected methane is passed over the electrically interconnected catalysts. Methane gas contained in the gas stream is oxidized only by the palladium catalyst while all other oxidizable components of the gas stream are oxidized by both catalysts.

Abstract: Methods and apparatus for interacting carriers with a structure of matter employ an electrode for emitting said carriers at a distance from a surface of that structure, and cause such carriers to travel along ballistic trajectories inside that structure by providing along the mentioned distance a gap for performance of a process selected from the group of carrier tunneling and field emission and injecting carriers emitted by the mentioned electrode and that process ballistically into the structure through the gap and the mentioned surface. The carriers are collected or analyzed after their travel along ballistic trajectories in the structure of matter. Pertinent information on the inside of the structure is obtained by conducting inside that structure what conventionally would have been considered external ballistics, while performing the carrier-propelling internal ballistics conversely outside that structure.

Abstract: A method is disclosed for making planar oxygen-solid electrolyte sensors. The method involves coating the several layers onto a support, selectively etching an etchable layer to form areas wherein the electrode layers and electrolyte layers may be formed thereon and, finally, etching the etchable layer totally away in order to form a chamber therein.

Abstract: A metal and an insulator are alternately deposited on a substrate. The alternate deposition is continued until the desired film thickness of the cermet is obtained, at least one of the metal or insulator materials being deposited in sufficiently small quantities so that only a discontinuous film of that material is formed during a deposition. The metal insulator composition of the cermet is controlled by the relative deposition rates of the insulator metal. The metal particle size is controlled by the duration of each metal deposition.

Abstract: This specification discloses a method of making a titanium dioxide element (20) which can be used as an oxygen sensing element. The method involves the selection of at least a pair of electrically conductive leads (12--12) which resist oxidation at high temperatures. The leads are placed in a position generally close to one another with a slurry bridgeable space therebetween. Slurry (14) is applied to the pair of spaced leads. The slurry contains titanium dioxide, an organic heat decomposable binder, and an organic solvent. The slurry is one that when applied to the pair of spaced leads the surface tension of the slurry draws it into a compact generally spherical shape about the pair of spaced leads. The slurry is dried, heated and sintered so that the titanium dioxide particles contained in the slurry are sintering together to form a titanium dioxide oxygen sensing element bridging the bridgeable space between the pair of spaced leads.

Abstract: A circuit (10) for obtaining a voltage reading (V.sub.o) from a sensing element is characterized by the following structure. A first circuit (12) connects a first end (14) of a voltage source (16) to a first end (18) of a resistance heater (20). A second circuit (22) connects a second end (24) of the voltage source to a second end (26) of the resistance heater. A sensing element (28) has two leads (30,32). A third circuit (34) connects lead (30) of the sensing element to an external circuit (36). A load resistor (40) is coupled between the second circuit and the third circuit. An interconnecting circuit (42) couples lead (32) of the sensing element intermediate the resistance heater. The electrical resistance of resistance heater is substantially less than the electrical resistance of the sensing element.

Abstract: A method is disclosed for making a titanium dioxide element which can be used as an oxygen sensing element. The method includes obtaining a substrate for supporting a titanium dioxide film and placing that substrate in a vacuum chamber. A vacuum is drawn on the vacuum chamber and the chamber is heated to a temperature in a range from 400.degree.-700.degree. C. A low pressure carrier gas containing 1-10% by volume of oxygen along with a coating gas formed from an organometallic compound of titanium is flowed over the substrate. The coating gas is one which is heat decomposable into a titanium dioxide coating on the heated substrate. The coating gas and the carrier gas are at a total pressure from 100-200 Pa. The coating gas and carrier gas are flowed over the substrate until a titanium dioxide film of required thickness is built up. After formation of the required thickness of the titanium dioxide film, the substrate is removed from the vacuum chamber and heated to a temperature in a range from 800.degree.