Abstract: A method and device, employing positive-temperature-coefficient material, for sensing plural properties of a fluid, such as temperature and flow rate. Can be used in a wind gauge or in a device for sensing position of mechanical elements such as valve diaphragms. Single sensor device, with energy and ohmic resistors, produces two voltages which completely characterize temperature and flow rate of fluid under study.

Abstract: A sensing and measuring circuit, employing a positive-temperature-coefficient sensing device, for detecting the presence and approximately measuring the quantity or concentration of heat-absorptive substances such as water. May be used for sensing a quantity of rainfall or irrigation water, or for detecting and giving an alarm or initiating remediation for leakage of water, oil, or other fluids from confinement to an unauthorized location.

Abstract: A sensor and associated circuitry for sensing and reacting to the presence of a fluid or other material having heat capacity. A positive-temperature-coefficient device initiates a switching step when the amount of heat-capacity material reaches a certain level, or is totally absent. The switching step may trigger an alarm or control circuit to rectify the fluid level.

Abstract: A sensing and measuring circuit, employing a positive-temperature-coefficient sensing device, for detecting the presence and approximately measuring the quantity or concentration of heat-absorptive substances such as water. May be used for sensing a quantity of rainfall or irrigation water, or for detecting and giving an alarm or initiating remediation for leakage of water, oil, or other fluids from confinement to an unauthorized location.

Abstract: A sensor and associated circuitry for sensing and reacting to the presence of a fluid or other material having heat capacity. A positive-temperature-coefficient device initiates a switching step when the amount of heat-capacity material reaches a certain level, or is totally absent. The switching step may trigger an alarm or control circuit to rectify the fluid level.

Abstract: A method and device, employing positive-temperature-coefficient material, for sensing plural properties of a fluid, such as temperature and flow rate. Can be used in a wind gauge or in a device for sensing position of mechanical elements such as valve diaphragms. Single sensor device, with energy and ohmic resistors, produces two voltages which completely characterize temperature and flow rate of fluid under study.

Abstract: The invention relates to a device for correcting error in temperature readings caused by thermocouple-to-extension wire ambient temperature fluctuations. The device creates an isothermal mass which raises the temperature of terminals to higher than ambient temperature. The isothermal mass consists of a self heating thermistor surrounded by thermal conductive epoxy inside an isothermal mass which contains the terminals. The isothermal mass is enclosed within insulating discs using a closure casing to complete the assembly. Using these higher than ambient temperature terminals for the connection between a thermocouple and extension wires, any error due to ambient temperature fluctuations is minimized.

Abstract: A dual-function scavenger system, especially useful in conjunction with ovens for processing semiconductor materials, wherein the spent process gases from the ovens are separated from their residual thermal energy for disposition through discrete channels. Back diffusion of atmospheric air into the ovens is minimized.

Abstract: Mass flow of a fluid flowing in a conduit is detected by mounting an active device in thermal contact with an external wall of the conduit, the active device being characterized by a positive temperature coefficient of resistance of at least 10%/.degree.C. for a range of temperatures, driving the active device to operate within the temperature range, and detecting mass flow based on the resistance of the active device. In another aspect, a passive temperature sensor is arranged to sense the temperature of the fluid at one position along the conduit, the passive temperature sensor being substantially non-self-heating, an active device is positioned to exchange heat at another position along the conduit, the conduit having a resistance dependent on temperature, and mass flow is detected based on signals from the active device and from the sensor.

Abstract: A full round bushing is formed by laser welding opposed edges of a bimetal member deformed into a generally cylindical configuration. The laser beam parameters are closely controlled so as to limit any adverse affect on a bearing metal layer. The weld only reaches a depth approximately 20% to 75% of a steel reinforcing layer. The beam approaches the seam between opposed edges at an angle of incidence approximately 10.degree. to 45.degree. and at a laser focal point offset 5% to 70% of the spot diameter of the laser beam. An overlap of the pulse spot-welding approximately 50% to 75% is preferable. A machine vision control system is used to locate the seam, moving the bushing to position the seam as desired relative to the laser and to trigger the laser to perform the welding operation.

Abstract: An automatic microprocessor-based control system for a diffusion furnace in which the controller is dedicated to a single associated diffusion tube to provide all monitoring and control functions necessary for a variety of diffusion processes. The controller provides direct digital control of time, temperature and gas flow, and can be readily operated with a variety of control algorithms.