Abstract: A testing and measuring apparatus and method is described for determining the accuracy of pressure transducers under test and for accurately measuring the pressure of a fluid. Accurate calibration of a referenced pressure transducer and automatic correction of the output signal produced by the reference transducer are features of the system. Specifically, the test system includes a reference pressure transducer, input and output fluid ports, solenoid control valves, a microcomputer and a key pad. Input to the reference pressure transducer is coupled to the solenoid control valves which are respectively coupled to the pressure standard, to atmosphere and to the input and output fluid ports. The output of the reference pressure transducer is coupled to a microcomputer programmed to automatically correct the output signal from the reference pressure transducer for certain predetermined inaccuracies and is also preferably programmed to control the operation of the solenoid control valves.

Abstract: A linear variable differential transformer pressure transducer includes a pressure sensing element which is deformed in response to changes in the pressure of a fluid. The pressure sensing element is connected to the core of a differential transformer, the coils of which are mounted on a dashpot within which the core is disposed. The dashpot is filled with a damping fluid which surrounds the core. The core enters the dashpot through an opening in a flexible boot which covers the open end of the dashpot to prevent leakage of the damping fluid. The pressure transducer serves to suppress destructive harmonic resonances of the Bourdon tube by imparting a variable restraining force on the linear movement of the core. The pressure transducer exerts a minimal restraining force to the low frequency movements of the core caused by normal fluctuations in the fluid pressure, but exerts a high restraining force against sudden pressure transients or vibration near the pressure sensing element's resonant frequency.

Abstract: Air trim control actuator mechanically connects a fuel flow device to an air flow device for setting the air to fuel ratio in combustion apparatus. An air to fuel ratio control unit is responsive to electrical input signals from an oxygen sensor that monitors the combustion products in the stack emissions. The air trim actuator includes a pivotally mounted input arm that is mechanically connected to the control unit and is pivoted to a preselected position corresponding to the selected boiler load. The input arm is connected by a link to an output arm which is pivoted through a preselected range of movement to control the position of the damper. The output arm has an elongated arcuate slot for receiving the end of the link. The output arm is pivoted to a position corresponding to the pivoted position of the input arm for selectively positioning the damper to provide air flow to the boiler for the desired air/fuel ratio.

Abstract: A system for extending the temperature range over which diffused semiconductor strain sensing devices specifically can be used includes a semiconductor chip having a base material and a semiconductor device formed in the base material. Biasing potential is applied to the base material and excitation potential applied to the diffused device. The biasing potential and the excitation potential are selected relative to one another to permit a predetermined variation in the semiconductor device characteristic with temperature over an extended temperature range. In the semiconductor strain sensing application, this predetermined characteristic is the impedance of the device. In this way, compensation for the variation of the characteristic can be applied to extend the useful temperature range for the semiconductor device.

Abstract: A gram beam force gauge has a housing having a peripheral wall and a partition with a front face and a rear face substantially perpendicular to the peripheral wall. A pointer overlies a dial mounted on the front face of the partition and is mounted on a rotatable shaft passing through the partition. A pinion on the shaft to the rear of the partition engages a sector gear mounted on a drum which in turn is rotatably mounted adjacent the rear face of the partition on an axis parallel to the axis of the pinion. A flexible band passes around the drum and has each free end connected to one end of an extension coil spring. The first spring has its outer end secured to the housing and the second spring has its other end secured to a slide for preloading the springs and zero adjusting the pointer. A force transmitting beam is secured to the drum and extends beyond the housing. Advantageously, the slide is a slotted block retained by a headed screw secured to the partition.

Abstract: An apparatus for sensing the condition of a pressurized fluid including a semiconductor chip having a diaphragm portion adapted for exposure to the pressurized fluid and an adjacent terminal portion adapted for connection to external circuitry for providing a measurement of the condition of the fluid. The semiconductor chip has sensing elements formed within the diaphragm portion and conductor elements in electrical contact with the sensing elements formed within and extending from the diaphragm portion to the terminal portion. A fluid barrier is provided for isolating the diaphragm portion from the terminal portion to prevent the terminal portion from being exposed to the pressurized fluid, while permitting pressurized fluid to contact the diaphragm portion so that the condition of the pressurized fluid can be sensed.

Abstract: Improved paint brush bristles and provided from a blend of nylon 6/6 or nylon 6/12, together with between 4-15%, depending upon the shape and size of the filament, of a co-polyester derived from terephthalic and isophthalic acids with cyclohexane dimethanol.

Abstract: Improved paint brush bristles formed of synthetic materials are hollow and tapered with a central axial hollow. The tapered hollow bristles are characterized by their consistent wall thickness, i.e., ratio of cross-sectional hollow area to cross-sectional wall area remains consistent from one end of the bristle to the other; and by their consistency in neck-down location.

Abstract: Solar energy collector assembly including a solar energy collector in an enclosed space housing with bottom closure member secured by a snap-fit spring channel and low thermal conductivity mating projection therefor, a collector member securing means comprising a plurality of stiff low thermal conductivity wire retainers and top cover securing and sealing means comprising a seal and clamp engaging the top cover just inward of its periphery, to prevent intrusion of condensate in the enclosed space of the housing.

Abstract: A method of treating liquid waste with ozone by passing the liquid to be treated between complementary horizontal electrodes having therebetween electrically conductive particles so as to form an electrode bed, pulsing air simultaneously with said liquid, and maintaining between said electrodes an electrical potential so that as the air and liquid pass through said electrode bed, the bed expands to establish electrical contact between the electrodes thus to create localized arcing between particles in the bed and to form ozone.

Abstract: Photovoltaic cell comprises thin film cadmium telluride in ohmic contact with a conductive substrate, preferbaly comprising a cadmium surface, through a cadmium-rich layer at the interface with the substrate. The cell further includes a rectifying barrier layer which may be a Schottky barrier. The film is electrodeposited on the substrate surface and the substrate materials and electrodeposition conditions are controlled so as to produce a substantially stoichiometric deposit. Preferably, the film or cell is subsequently treated to enhance its efficiency.

Abstract: A filtration assembly including a perforate basket, screen and filtration media is provided with bands of complementary releasable attachment means along mating surfaces. The complementary releasable attachment means permit the backing screen and filtration media to be installed in and removed from the perforate basket simply without tools, while retaining the backing screen and filtration media in proper alignment with the perforate basket during the filtration process.

Abstract: Improved solar collector sub-assemblies and combinations thereof includes corner-locking piece sub-assemblies, top glazing clamping member sub-assembly, collector plate mounting member sub-assembly and collector assembly mounting means, all adapted to facilitate assembly and installation of collectors in accordance with the present invention and to permit thermal expansion of components thereof.

Abstract: Improved paint brush bristles formed of synthetic materials are hollow and tapered with a central axial hollow. The tapered hollow bristles are characterized by their consistent wall thickness, i.e., ratio of cross-sectional hollow area to cross-sectional wall area remains consistent from one end of the bristle to the other; and by their consistency in neck-down location.

Abstract: The invention relates to solar collectors which transfer thermal energy from a collector to a point of use by means of a heat exchange fluid. An array of collectors may be provided having a modified system to facilitate convenient assembly into an array and to provide balanced fluid flow across the array. The outlet conduit sized to insure the steady flow of fluid and air thus preventing the accumulation of air to the outlet to block fluid flow.

Abstract: A switch device is used in a self-retracting cord reel having a housing, a rotating drum, and an electrical cord having a portion thereof wound on the drum, a spring motor for rewinding the cord on the drum, a ratchet, a pawl having a first stop position for engaging the ratchet to stop the reel from rewinding the cord and a second position permitting the reel to rewind the cord, the positioning of the pawl being controlled by the movement of the reel with the cord. A switch is secured to the drum in circuit with the cord and is biased to one of its two positions. Switch operating mechanism is adapted to be moved by the pawl for placing the switch in the other position when the pawl is in its stop position.

Abstract: Solar energy collector assembly including a solar energy collector in an enclosed space housing with bottom closure member secured by a snap-fit spring channel and low thermal conductivity mating projection therefor, a collector member securing means comprising a plurality of stiff low thermal conductivity wire retainers and top cover securing and sealing means comprising a seal and clamp engaging the top cover just inward of its periphery, to prevent intrusion of condensate in the enclosed space of the housing.

Abstract: Photovoltaic cell comprises thin film cadmium telluride in ohmic contact with a smooth conductive substrate, preferably comprising a cadmium surface, through a cadmium-rich layer at the interface with the substrate, the cell further including a rectifying barrier layer. Preferably, the film is electrodeposited on the substrate surface with specific materials and process conditions. Preferably also, the film or cell is subsequently treated to enhance its barrier layer interface function.

Abstract: A wet pick-up type vacuum motor fan unit with a separately ventilated motor section and a motor end bracket serving also as a support for, and part of a discharge end housing wall for, the working air fan section, has on the bracket fanward face a centrally apertured metal disk plate defining a flow space or path for bearing sealing air flow from ambient air inlets external of the motor section to a central discharge into the inlet eye of an auxiliary fan clamped on the shaft back-to-back with a larger diameter working air centrifugal fan adjacent the end bracket.