Abstract: A thermostat includes a housing having a cavity formed therein, a temperature responsive bimetallic disc located in the housing, a stationary contact member which is electrically interconnected to a first terminal external to the housing, and a movable contact member which is electrically interconnected to a second terminal external to the housing. The movable contact member movable between a switch-closed position and a switch-open position. An actuating member is located in the housing and is responsive to flexing movement of the disc for moving the movable contact member from the switch-closed position to the switch-open position. A reset assembly is provided for resetting the disc, and includes a reset element which is movable between a first position in which it is spaced from the actuating member and a second position in which it is axially moved to engage the actuating member for moving the disc back to its pre-flexed position.

Abstract: The present invention is directed to iron sensors. Immobilized in close proximity of the potential or pH measuring surface of a proton sensing device, minute quantities of an iron chelator such as siderophores or transferring cause detectable variation of the potential or pH upon the binding of iron. The sensing devices for measuring this change in potential or pH include the iron chelator-modified ion-selective field effect transistors (IC-ISFET) and/or pH indicator papers of the present invention.

Abstract: A microwave motion sensor for detecting multiple levels of motion of a target is disclosed. The motion sensor includes a transceiver for broadcasting a signal into a predetermined area and receiving a reflected signal with a receiver for producing first and second directional signals. A signal conditioning circuit is provided for amplifying the first and second directional signals and digitizing the directional signals. The signal conditioning circuit includes a micro motion amplifier for separately amplifying one of the directional signals and producing a micro motion signal. A processor is provided for receiving the first and second directional signals transmitted by the signal conditioning circuit, and for receiving the micro motion signal. The processor includes a circuit for analyzing the directional signals, and a circuit for comparing the micro motion signal to a threshold.

Abstract: Apparatus for measuring a characteristic of motion and methods for its manufacture are disclosed in which a sensor structure includes a support structure, and a mass suspended from such support structure by a spring connecting arrangement and electrical devices for measuring displacement of the mass which results from a force applied to the support structure. An apparatus is provided where the mechanical spring constant of the connecting arrangement of the sensor structure is provided to be a high value representative of a strong, stiff spring which resists breaking due to high forces applied to it, and where an electric spring constant is provided to yield a small effective sensor spring constant K.sub.eff =K.sub.m -K.sub.e. Methods are also provided to manufacturing the apparatus by specifying the mechanical spring constant and providing an electric spring constant which will yield a desired effective spring constant which produces a desired characteristic of the sensor structure.

Abstract: A micromachined structure for handling fluids with an applied high voltage, i.e. for electrophoresis, includes a glass or other highly insulative substrate on which are formed very small diameter capillary channels of e.g. silicon nitride. Due to the absence of a silicon substrate, this structure is highly electrically insulative. The silicon nitride channels are formed by a micro-machining and etch process, so that they are initially defined in an etched sacrificial silicon wafer by conformal coating of etched features in the silicon wafer with a silicon nitride layer, which is then patterned to define the desired channels. The silicon wafer is bonded to the glass substrate and the bulk of the silicon wafer is sacrificially etched away, leaving the desired silicon nitride channels with supporting silicon mesas. The remaining silicon nitride "shell" is bonded to the glass substrate and substantially duplicates the etched features in the original silicon wafer.

Abstract: A meandering winding magnetometer (MWM) includes a meandering primary winding and at least one sensing winding or coil on a membrane to be pressed against a test surface. The membrane may be supported on a flexible carrier which is translatable into a probe. Abutments in the probe press the carrier against the test surface but allow the carrier and membrane to conform to the test surface. One MWM circuit includes meandering primary and secondary windings. The return leads from the secondary winding return to connector pads in close alignment with the test array, while leads from the primary winding are spaced at least one wavelength from the array. In another MWM circuit, individual sensing loops are positioned within the meandering primary winding. The MWM circuit may be provided on an adhesive tape which may be cut to length.

Abstract: Method and apparatus for determining deterioration of e.g. lubricating oil by measuring the electrical properties of a polymeric matrix (support) holding charged ionic groups. The dynamic range of the device is increased by creating a local polar environment formed around the charged groups of the polymeric matrix and by exploiting bead shrinkage with increasing degradation (or solvent polarity). Both approaches can be further employed in a single sensor by the use of multiple chambers containing a combination of the above. Also, contaminant detection is improved by detecting changes in amplitude and/or frequency of noise output. The sensor can also be used to detect a level of oil for instance in an engine oil pan.

Abstract: Method and apparatus for determining deterioration of e.g. lubricating oil by measuring the contraction of a polymeric matrix (support) holding charged ionic groups. The support contracts due to oil quality degradation. The expansion/contraction is detected e.g. electrically.

Abstract: A sensor structure (10) has a central mass (16) mounted within a support structure comprising an outer frame (18) with upper and lower covers (12, 14). Eight L-shaped or elbow-shaped ribbon springs are fit about the corners (28) of the mass (16) to allow mass (16) for movement from a reference position with respect to the support structure. One leg of each spring is connected to the middle of an associated side (26A) of the mass (16) while the other leg is connected to the outer frame (18). According to an alternative embodiment, each of the springs (72) is characterized by a relatively larger width at spring-mass connection point (74) and at spring-support connection point (73) and a relatively smaller width at an elbow-bend region between connection points.

Abstract: A thermostatic switch has a housing and a temperature responsive bimetallic disc located in the housing and responsive to a predetermined temperature for exerting a flexing action. A fixed contact member is located in the cavity along with a movable contact member which is biased and movable between a switch-closed position in which it makes electrical contact with the fixed contact member and a switch-open position in which it is spaced from the fixed contact member. An actuating member is located in the housing, and is responsive to flexing movement of the disc for moving the movable contact member from the switch-closed position to the switch-open position. A hook portion is mounted within the cavity of the housing, the hook portion engaging an arm portion of the movable contact member upon the movement of the movable contact member to its switch-open position and entering an opening of the arm portion for retaining and maintaining the movable contact member in its switch open position.

Abstract: A sensor structure (10) has a central mass (16) mounted within a support structure comprising an outer support frame (18), and upper and lower plates or covers (12, 14). Eight L-shaped ribbon springs (32, 34) fit about the corners (28) of the mass (16) to mount mass (16) for movement from a reference position with respect to the support structure. One leg (38) of each spring (32, 34) is connected to an associated side (26A) of the mass (16) centrally of the length of the associated side (26A). The other leg (40) is connected to the outer support frame (18). The sensor structure is designed for use as a sensing mechanism in an electrostatic accelerometer arrangement.

Abstract: Micro-machined accelerometer chips have a sensitive axis perpendicular to the principle surface of the device. In an application where the desired sensing direction is in the plane of a supporting printed circuit board, the accelerometer cannot be mounted directly on the printed circuit board and instead is mounted on a wall perpendicular to the printed circuit board. This requirement to wall-mount the sensor is eliminated by using an accelerometer chip packaged with a signal conditioning circuit in a multi layer ceramic chip carrier. Electrical connections are contained within the layers of the ceramic and terminate at a side surface of the chip carrier. Thus the accelerometer chip sits perpendicular to the printed circuit board and the ceramic chip carrier is attached directly thereto.

Abstract: An automatic calibration technique for a gas analyzer includes applying electrical energy to a source that is different from the level used to detect gas concentration in order to produce a different level of radiation from that used to detect gas concentration. The reduced level is applied with a non-absorbing gas in the gas sample chamber. The detector output at the reduced level is resolved to a calibration factor. The instrument can be linearized by repeating the calibration procedure at multiple different levels of reduced source radiation. In one embodiment, a source assembly is provided that includes a plurality of infrared emitters to which is applied modulated electrical energy in a timed sequence in order to produce output levels for three component gas concentrations. A filter between each one of the sources and a detector pass radiation at an absorption line of one of the component gases.

Abstract: A precise fluid flow meter fabricated by micromachining techniques measures a wide range of fluid flow rates. Two serial portions of an enclosed channel have different cross-sectional areas, and therefore different flow velocities. The fluid carries the thermal pulse through the flow channel to two sensor elements spaced apart along the channel downstream from the heating element. The transit time of the thermal pulse between the two sensor elements measures the fluid flow velocity.

Abstract: A gas sensor comprises a substrate on which are mounted three cells. Each cell includes an interdigitated capacitor defined by a pair of comb structure, electrically conductive tracks with the fingers of the combs interleaved. The tracks of each capacitor are covered by an insulating and chemically inert protective coating of an electrolyte. A monitor monitors one of a resistive component and a capacitive component of the relative dielectric constant of the electrolyte independently of the other component.

Abstract: An automatic calibration technique for a gas analyzer includes applying electrical energy to a source that is different from the level used to detect gas concentration in order to produce a different level of radiation from that used to detect gas concentration. The different level is applied with a non-absorbing gas in the gas sample chamber. The detector output at the reduced level is resolved to a calibration factor. The instrument can be linearized by repeating the calibration procedure at multiple different levels of reduced source radiation. In one embodiment, source assembly (26) is provided that includes a plurality of infrared emitters (36) to which is applied modulated electrical energy in a timed sequence in order to produce output levels for three component gas concentrations. A filter (56) between each one of the sources (36) and a detector (50) pass radiation at an absorption line of one of the component gases.

Abstract: Micro-machined accelerometer chips have a sensitive axis perpendicular to the principle surface of the device. In an application where the desired sensing direction is in the plane of a supporting printed circuit board, the accelerometer cannot be mounted directly on the printed circuit board and instead is mounted on a wall perpendicular to the printed circuit board. This requirement to wall-mount the sensor is eliminated by using an accelerometer chip packaged with a signal conditioning circuit in a multi layer ceramic chip carrier. Electrical connections are contained within the layers of the ceramic and terminate at a side surface of the chip carrier. Thus the accelerometer chip sits perpendicular to the printed circuit board and the ceramic chip carrier is attached directly thereto.

Abstract: A melt pressure measurement probe for insertion through wall of melt-containing vessel has a pressure-deflectable end portion for contact with pressurized melt. Pressure-resistant securing means fixes the end surface in a non-flow obstruction relationship. A seal surface on the probe prevents exposure of the melt to the securing means. Pressure detection means internal of the probe, responsive to deflection of the probe end surface to detect melt pressure, comprises a temperature-compensated capacitive sensor, one capacitor plate defined by the end portion and an opposite capacitor plate in the probe with a capacitive gap in-between. Electronic circuitry remote from the melt-exposed end, including circuitry within the probe to generate a signal proportional to the capacitance, compensates for change of temperature of the capacitor to generate an output signal proportional to melt pressure.

Abstract: A method for fabricating a connecting spring member (24) of an arbitrary shape extending between a central mass (21) and an outer support frame (23) of a sensor as shown in FIG. 7 is disclosed. Each of a pair of generally identical silicon wafers (10, 12) has an inner etch stop layer (16) applied to one face with an outer epitaxial layer (18) formed over such etch stop layer (16). A photosensitive oxide layer (30) is applied to the other face of each of the wafers (10, 12). Next, a pattern of the central mass (21) and outer support frame (23) as shown in FIG. 2 is photographically imposed on the photosensitive oxide layers (18) of each wafer (10, 12). After wet chemical etching of the wafers (10, 12) removes silicon material to the etch stop layer, and the etch stop layer is itself removed in the space between the mass and the frame, the two wafers (10, 12) are bonded to each other as shown in FIG. 5 .