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: 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: 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 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 .

Abstract: A pattern processing system associates image input patterns with desired response codes. The image input is stored in an image buffer as an addressable array of sample values. An address sequencer provides a sequence of addresses (or "address stream") to the image buffer and to a response memory. The next address provided by the address sequencer is based upon the current address and the state of the sample value stored in the image buffer at the location corresponding to the current address. Once the address sequencer repeats and address, the address stream is in a repetitive address loop as long as the image stored in the image buffer remains constant. The address loop continues to be generated since the address sequencer always produces the same next address based upon the same current address and the same sample value stored at that current address.

Abstract: A pattern processing system associates image input patterns with desired response codes. The image input is stored in an image buffer as an addressable array of sample values. An address sequencer provides a sequence of addresses (or "address stream") to the image buffer and to a response memory. The next address provided by the address sequencer is based upon the current address and the state of the sample value stored in the image buffer at the location corresponding to the current address. Once the address sequencer repeats and address, the address stream is in a repetitive address loop as long as the image stored in the image buffer remains constant. The address loop continues to be generated since the address sequencer always produces the same next address based upon the same current address and the same sample value stored at that current address.

Abstract: An apparatus and method of operation for a self-testable accelerometer having a housing, a diaphragm for detecting movement in response to an applied force, a mass on the diaphragm, at least one capacitive plate attached to the housing and disposed such that a potential difference between the capacitive plate and the mass causes a movement of the mass, means for producing a potential difference between the mass and the capacitive plate, and at least one piezoresistive element attached to the housing and the diaphragm for sensing movement of the mass. The accelerometer's housing comprises a frame, a base and a cap with air gaps providing squeeze film damping and mechanical stops for inhibiting movements of the mass. The combination of the capability to electrostatically produce a movement of the mass and the piezoresistive sensing of that movement allows testing and calibration of the accelerometer at any stage in its manufacture or deployment without the need for external equipment such as shakers.

Abstract: A process for forming a three-dimensional structure etched in a substrate with perfect convex corners includes partitioning the structure into two features such that the exterior corners are formed by the intersection of the two features; etching the first feature; forming an etch mask on the surface and on the substrate of the etched first feature; opening a window in the etch mask on the substrate to define the second feature; and etching the second feature, thereby obtaining the desired structure.

Abstract: A method for making a groove of a precise width in a substrate material. The groove may have any cross-sectional shape. The groove is formed by initially etching the substrate material. The groove width is then measured. The measured groove width is compared to the desired groove width. Oxide is grown on the substrate in the region of the groove to adjust the width of the groove. The oxide may or may not be grown with the original etchant mask left on the substrate. Depending on whether it is desired to increase or decrease the groove width, the oxide is or is not removed. The process for increasing or decreasing groove width may be repeated any number of times as necessary to achieve a proper groove width. A number of grooves may be formed using these processes. For many applications, the groove will be covered with a plate or other type of cap to define a channel as used in flow restrictors.

Abstract: A bimetallic disc assembly for a bimetallic disc-actuated thermostatic switch includes a disc retainer, a bimetallic disc received in assembled position on the disc retainer and a metallic retainer cap for retaining the disc in assembled position on the disc retainer and for securing the assembly to the body portion of the thermostatic switch. The disc retainer is adapted to minimize heat flow from the metallic cap to the disc retainer by minimizing the areas of contact between the disc retainer and the cap. The disc retainer is integrally formed from a ceramic material and it includes a central hub having an axial bore extending therethrough, a circular flange extending radially outwardly from the hub, a circular shoulder extending upwardly from the flange, and a peripheral rim extending upwardly from the shoulder. The peripheral rim includes a horizontal edge with a plurality of circumferentially spaced projections or bumps which extend upwardly therefrom.