Abstract: Apparatuses for controlling gas flow are important components for delivering process gases for semiconductor fabrication. In one embodiment, an apparatus for controlling gas flow is disclosed, the apparatus delivering two gas flows at a known ratio. Specifically, the apparatus has first and second on/off valves and first and second flow restrictors. The first and second on/off valves may be altered between an open state and a closed state. When both the first and second on/off valves are in an open state, first and second gas flows are delivered to first and second outlets. The first and second gas flows are provided at a known ratio to one another, this ratio determined by the ratio of the resistance to flow of the first and second flow restrictors.

Abstract: Methods, systems, and devices for combining an over-the-air broadcast signal with another digital media signal are described. Broadcast signals may be received at a user's location, demodulated, and then remodulated using the modulation scheme of a non-broadcast signal. The remodulated broadcast signal may then be combined with the non-broadcast signal, and the combined signal may be transmitted to a user's video equipment. In some cases, a channel guide interface may be provided that includes both the broadcast and non-broadcast media channels.

Abstract: A system and a method detect contamination of a diaphragm in a capacitance diaphragm gauge wherein a contaminated diaphragm deflects less in the presence of pressure than an uncontaminated diaphragm. The system and method measure a base pressure. A DC voltage is applied between the diaphragm and a fixed electrode to cause the diaphragm to deflect to simulate an effective pressure. The system and method measure a combined pressure caused by the base pressure and the effective pressure. The system and method subtract the base pressure to determine the effective pressure caused by the static diaphragm deflection. If the measured effective pressure is less than an acceptable effective pressure, the system and method determine that the diaphragm is contaminated.

Abstract: A system and method detect the presence of an unacceptable quantity of gas molecules in the reference vacuum cavity of a capacitance diaphragm gauge (CDG). An independent pressure transducer has an active portion exposed to the reference vacuum cavity. The transducer includes a ring anode, a cylindrical inner wall surface that forms at least one cathode, and a magnet positioned with respect to the ring anode such that the magnetic flux of the magnet is generally aligned with the central axis of the ring anode. A high voltage source applies a voltage between the ring anode and the cathode. A current sensor senses a magnitude of any current flowing between the ring anode and the cathode via ionized gas molecules. A monitoring unit monitors the magnitude of the current sensed by the current sensor and activates an alarm when the magnitude of the current exceeds an acceptable magnitude.

Abstract: A system and method mitigate the effects of these external vibrations on a capacitance diaphragm gauge by sensing the motion of the diaphragm at the first natural frequency of the diaphragm of the CDG. The presence of the natural frequency signals superimposed on the pressure signal is determined by sensing variations in the output of a sensor at or near the known natural frequency of the diaphragm and filtering that known low frequency from the output. The filtered signal is used in a feedback circuit to impose electrostatic forces on the diaphragm. The imposed electrostatic forces oppose the motion created by the external vibration to suppress the effects of the vibration on the pressure measured by the CDG.

Abstract: In order to mitigate the negative effects of a change in atmospheric pressure, an improved capacitance diaphragm gauge (CDG) sensor incorporates an independent ambient atmospheric pressure sensor near the CDG sensor body. The ambient atmospheric sensor is located outside the CDG sensor body to sense the ambient atmospheric pressure surrounding the CDG sensor body. The ambient atmospheric sensor provides an output that represents the ambient atmospheric pressure. A sensor output processing circuit receives the output of the ambient atmospheric sensor as well as the output of the CDG sensor. The processing circuit utilizes the output from the ambient atmospheric pressure sensor to fine tune the CDG measurement of pressure by executing an in situ, real time, automatic calibration adjustment of the CDG.

Abstract: Smokehouses (20) or other similar thermal processing cabinets or houses are provided with improved floor assemblies (22) which eliminate fluid collection and provide a high degree of structural integrity. The smokehouses (20) include upright walls (24, 26) supported on the floor assemblies (22). Each floor assembly (22) has one or more weldment frame assemblies (38) including a peripheral frame assembly (46) with opposed wall receiving channel segments (52) and frame elements (54). Drainage structure such as one or more tubular drain units (44) are also preferably secured to the weldment frame assemblies (38) and are positioned to effect proper liquid drainage. Tread plates (42) are secured to the weldment frame assemblies (38). In order to construct a floor assembly (22), an appropriately sized recess (66) is formed and the weldment frame assemblies (38) and drain units (44) are installed. A monolithic pour of concrete (40) is then placed within the weldment frame assemblies (38) and allowed to cure.