Abstract: A reduced pressure reaction chamber allows rotation of a workpiece, and translation of the workpiece along the axis of rotation, using a sealed rotate and translate actuator. The reaction chamber has rigid walls, and is particularly suited to reduced pressure systems. The actuator includes a shaft coupled through the wall of the chamber by a vacuum rotary feed-through mechanism. A sleeve is mounted over the shaft and coupled to the shaft by means of threads, and shaft seals, which provide a frictional coupling between the shaft and the sleeve. Due to the frictional coupling, the sleeve attains the same rotational velocity as the shaft. A clutch is provided, which engages the sleeve when linear translational motion is desired. The difference in rotational velocity of the shaft and the sleeve is translated into linear motion by the threads. The shaft seals, in addition to providing the frictional coupling, seal the actuator, and reduce contamination caused by such mechanism.

Abstract: An analog to digital converter (ADC) is disclosed having a coarse converter to generate the most significant bits of the output and double folding interpolation circuitry to generate the least significant bits. Each side of the double folding circuit includes additional folding stages coupled to reference voltages above and below the full scale input range of the ADC to cancel offset errors and improve circuit linearity. The interpolation circuit includes one interpolation stage, having two multiplier networks, for each least significant bit. Each interpolation stage receives two pairs of signals from the preceding stage and outputs two pairs of signals to the next stage. One of the pairs of output signals from each interpolation stage is also sent to a latched comparator. The outputs of all of the latched comparators can be read directly as the ADC output bits without requiring a decoder.

Abstract: The system and method for pyrometrically determining the temperature of a semiconductor wafer within a processing chamber accurately determines the actual emissivity of the semiconductor wafer at a reference temperature using multiple pyrometers operating at different wavelengths. The pyrometers are calibrated for radiation received from the processing chamber and their responses are then corrected to provide the proper temperature indication for a master wafer at a known reference temperature to yield emissivity of the master wafer. Other similar wafers exhibiting extreme values of emissivity are sensed at the reference temperature to provide pyrometer responses that are corrected in accordance with the master emissivity, and such corrected responses are used to establish a correlation between emissivities and the corrected pyrometer responses.

Abstract: A heater assembly for heating a container of corrosive fluid includes a housing adapted to be located in a container of fluid to be heated, a sealed chamber located in the housing, a heater located in the chamber, an electrically conductive sleeve assembly secured to the housing, and a flexible conduit extending from the sleeve assembly and providing a passageway for conductors providing a source of power to the heater assembly. The flexible conduit includes an electrical conductor connected to ground which is located in the sleeve assembly and the sleeve assembly is swaged to compress the sleeve assembly into the electrical conductor to ground to the electrically conductive housing via the sleeve assembly.

Abstract: A parallel analog-to-digital converter having comparators in a sequence with two sets of logic gates having inputs electrically connected to selected primary and complementary outputs of the comparators.

Abstract: An on-line slurry ash monitoring system for evaluating the composition of coal slurries in coal preparation plants. A coal slurry is introduced into a sample reservoir where it is removed and passed through a closed loop slurry transport system which causes the sample to be directed through a sensor and recirculated back to the reservoir. In order to enhance sensor accuracy, a sample is exposed to vacuum pressure conditions which removes gas bubbles and dissolved gases from the sample. The sensor is preferably a radiation absorption type in which characteristic absorptions of coal particles, ash and iron are evaluated by associated electronics to provide an output of slurry composition.

Abstract: Dual pyrometric detectors and method measure the temperature of a remote heated object in the presence of ambient radiation. One detector measures emitted radiation from both the remote object and from the environment, and the other direction measures radiation predominantly from the environment alone. The output signals from the two detectors are processed electronically to yield the detected radiation from the remote object alone. The result can then be electronically processed to display the pyrometrically-measured temperature of the remote object.

Abstract: An apparatus and method for separating hydrophilic particles from a fluid suspension containing both hydrophilic and hydrophobic particles. A generally cylindrical separation vessel includes tangential inlet and outlet ports. The fluid suspension is introduced into the separation vessel through the inlet port to circulate around the inner surface of the separation vessel in a forced vortex swirl flow. Air sparged through a porous wall portion of the side walls of the separation vessel forms air bubbles to which attach hydrophobic particles in particle/bubble aggregates. These migrate as a froth towards the axial center of the separation vessel where they are discharged at the upper end thereof. A froth washing tube having an open end proximate to the upper end of the separation vessel discharges pressurized water thereinto.

Abstract: An improved method and apparatus are disclosed for calibrating the emissivity characteristics of a semiconductor wafer within a processing chamber by supporting a sample wafer on a graphite susceptor within the chamber and by comparing the temperature measured within the susceptor in close proximity to the center of the wafer with the temperature measured by the emission of radiation from the surface of the wafer through the walls of the processing chamber. Temperature measurements subsequently made from the radiation emitted from the surface of similar wafers are corrected with reference to the measurement made of the temperature within the susceptor on the sample wafer.

Abstract: A self-regulating PTC heater assembly and a method of manufacturing the heater assembly is disclosed. PTC heater assembly includes a plurality of positive temperature coefficient devices, a plurality of spacers located between the positive temperature coefficient devices, a pair of metallic electrodes and a heat shrink tubing surrounding the pair of electrodes, PTC elements and spacers to hold the PTC elements and electrodes in place during assembly. A metallic sheath is compressed about the heat shrink tubing to establish uniform electrical contact between the PTC elements and the electrodes, to increase the thermal efficiency of the heater and to protect the heater assembly from physical damage.

Abstract: A converter, of the type having an R-2R resistive network and switches, is used to convert a digital signal of n-bits into an analog signal. A plurality of first interconnectors is used to electrically connect a first switch input of one of the switches to a first voltage reference node by separately extending directly therebetween. A plurality of second interconnectors is used to electrically connect a second switch input on the same one of the switches to a second voltage reference node is a similar fashion.

Abstract: A new and improved level controller for sensing the level of a fluid in a container is provided. The controller includes a heater with a thermocouple connected thereto and wherein the thermocouple is adapted to sense the temperature and the rate of rise of temperature. Immersion of the thermocouple in a fluid cools the thermocouple. When the thermocouple is not immersed in the fluid it is heated by the heating element to establish an alarm condition. An alarm condition is established when the rate of rise of temperature exceeds a predetermined rate of rise and/or when the temperature exceeds a predetermined maximum temperature.

Abstract: Radiation detectors and method measure the emissivity of a remote, heated semiconductor wafer in the presence of ambient radiation. Incident radiation within a selected waveband from a controlled source intermittently radiates the remote wafer, and reflected radiation therefrom is detected in synchronism with the intermittent incident radiation to yield output indications of emissivity of the wafer under varying processing conditions. The temperature of the wafer is monitored by another radiation detector (or detectors) operating substantially within the same selected waveband, and the temperature indications thus derived are corrected in response to the output indications of emissivity to provide indications of the true temperature of the wafer.

Abstract: An improved method and apparatus are disclosed for calibrating the emissivity characteristics of a semiconductor wafer within a processing chamber by supporting a sample wafer on a graphite susceptor within the chamber and by comparing the temperature measured within the susceptor in close proximity to the center of the wafer with the temperature measured by the emission of radiation from the surface of the wafer through the walls of the processing chamber. Temperature measurements subsequently made from the radiation emitted from the surface of similar wafers are corrected with reference to the measurement made of the temperature within the susceptor on the sample wafer.

Abstract: A system for thermally decomposing chemical materials efficiently and controllably heats input feed materials to very high temperatures for decomposition in the presence or absence of oxygen by heating means that may be disposed peripherally or intermediately of reaction zones may be of the protected type and may include preheating of feed material and process gas.

Abstract: A controller for operating an illumination source to illuminate selected objects to provide an image to an image transducer so that the illumination occurs at, or approximately at, the moment of time that the image of the object is desired to be acquired. An image signal manipulator receives signals corresponding to the image from the transducer.

Abstract: A thermal decomposition reactor accepts solid, liquid or gaseous waste products of industrial processes or the like and rapidly reduces same to substances such as carbon dioxide, water and glassified non-leachable ash without limitation by materials that may be commonly included in such waste.

Abstract: A flexible electric heating assembly for immersion heating of highly corrosive liquids, such as electroplating solutions, includes an iron-nickel-chronium resistance element disposed within a thin-walled stainless steel tube and electrically insulated therefrom by a magnesium oxide ceramic. The tube is enclosed in a tubular casing in direct contact with the tube and formed of resilient electrical insulating material having a low surface coefficient of friction and a high resistance to heat and attacks by corrosive liquids or vapors, e.g., polytetrafluroetylene. The ends of the tube terminate withn a non-corrosive junction box located outside the liquid to be heated, and in which box the connections between the power supply and heating element terminals are made.

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 an address stream containing a plurality of interleaved sequences of addresses to the image buffer and to a read/write response memory. The next address of each sequence provided by the address sequencer is based upon the current address of that sequence 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 an address in a sequence, that address sequence is in a repetitive address loop as long as the image stored in the image buffer remains constant. During a training mode, a pattern to be recognized is supplied to the image buffer and a training code representing a desired response is written into the response memory at selected locations that correspond to addresses in the address loop being generated.

Abstract: An address sequencer produces an address stream which includes a plurality of interleaved sequences of addresses. Each sequence is a function of input data which is received when an input pattern is sampled by that sequence, so that a repetitive address loop is generated which characterizes the pattern. The address sequencer includes a shift register with a programmable feedback circuit which provides a feedback bit to the first stage of the shift register based upon bits from selected stages of the shift register. During each operating cycle of the address sequencer, a counter provides a sequence identification number which identifies a particular sequence. A stored address selected by the sequence identification number is provided as the present address for that sequence (and the output of the address sequencer). In addition, the shift register is loaded with a multibit word derived from that stored address.