Abstract: A method of shielding a capacitive pressure transducer by positioning an insulated shield spacer between the capacitor electrodes, covering the two electrodes with an electrically conductive shield box, applying a sensor voltage from a first voltage source across the two electrodes, and applying a shield voltage from a second voltage source to the insulated shield spacer and to the shield box.

Abstract: A capacitive pressure transducer includes a shielded spacer positioned between the capacitor electrodes and driven with a separate voltage source.

Abstract: Heat resistant sensors equipped with any of a variety of transducers for measuring any of a variety of properties of fluids are constructed with components comprising materials that can withstand very high temperatures. Some embodiments of the sensors include a first pressure sensitive element and a second pressure sensitive element with respective first and second membranes positioned in juxtaposed relation to each other to form a capacitor. Some embodiments include a pusher that extends from the membrane toward a first electrode. Some embodiments have a housing comprising a ceramic substrate with a sensor element mounted on an inside surface of the substrate. Other embodiments have direction sensing capabilities including a heater positioned in a core material and at least three temperature sensors located at or near the peripheral surface of the core material and spaced apart angularly in relation to each other.

Abstract: An improved optical sensor and methods for measuring the presence of various materials or constituents in a fluid sample uses reactive material(s) in a fluid environment. The reactive materials have optical properties that change in the presence of a target material that may be present in the environment. An optical emitter generates light that is directed to the reactive materials, and one or more optical detectors receive reflected light from one or more interfaces in the optical path between the emitter and the detector(s), one or more of the interfaces having a reactive material. The reactive material(s), emitter(s), and detector(s) are selected based on the desired target material to be sensed.

Abstract: An improved optical sensor and methods for measuring the presence of various materials or constituents in a fluid sample uses one or more reactive materials in a fluid environment. The reactive materials have optical properties that change in the presence of one or more target materials that may be present in the environment. One or more optical emitters generate light that is directed to the reactive material(s), and one or more optical detectors receive light from the reactive material(s), and the presence or absence of the target material is determined based on the light received at the optical detector(s). The reactive material(s), emitter(s), and detector(s) are selected based on the desired target material to be sensed.