Abstract: An apparatus of mass flow controlling for use in an integrated gas delivery system, comprising an input terminal, an output terminal, a sensor unit, a flow rate control valve, and a control unit. The control unit comprises an A/D converter, a microprocessor, and a valve control circuit. The A/D converter converts an actual setting signal inputted by the input terminal into a first digital signal, and converts a flow rate detection signal outputted by the sensor unit into a second digital signal. The microprocessor further comprises a storage module, a setting signal calibration module and a calculation module. The valve control circuit generates, based on a control signal, an openness control signal, so as to control the flow rate control valve. It is concluded that the flow rate control quality is improved by the present invention.

Abstract: An apparatus of mass flow controlling for use in an integrated gas delivery system, comprising an input terminal, a sensor unit, an electromagnetic valve, and a control unit. The control unit comprises an A/D converter, a microprocessor, and a valve control circuit. The A/D converter converts a flow rate setting signal inputted by the input terminal into a first digital signal, and converts a flow rate detection signal outputted by the sensor unit into a second digital signal. The microprocessor further comprises a control module and a calculation module. The valve control circuit opens the electromagnetic valve according to the first control signal only, and further regulates an openness of the electromagnetic valve according to the first control signal and the second control signal. It is concluded that response time of the mass flow control apparatus of the present invention is shorten, and control quality is improved.

Abstract: An apparatus of mass flow controlling for use in an integrated gas delivery system, comprising an input terminal, an output terminal, a sensor unit, a flow rate control valve, and a control unit. The control unit comprises an A/D converter, a microprocessor, and a valve control circuit. The A/D converter converts an actual setting signal inputted by the input terminal into a first digital signal, and converts a flow rate detection signal outputted by the sensor unit into a second digital signal. The microprocessor further comprises a storage module, a setting signal calibration module and a calculation module. The valve control circuit generates, based on a control signal, an openness control signal, so as to control the flow rate control valve. It is concluded that the flow rate control quality is improved by the present invention.

Abstract: An apparatus of mass flow controlling for use in an integrated gas delivery system, comprising an input terminal, a sensor unit, an electromagnetic valve, and a control unit. The control unit comprises an A/D converter, a microprocessor, and a valve control circuit. The A/D converter converts a flow rate setting signal inputted by the input terminal into a first digital signal, and converts a flow rate detection signal outputted by the sensor unit into a second digital signal. The microprocessor further comprises a control module and a calculation module. The valve control circuit opens the electromagnetic valve according to the first control signal only, and further regulates an openness of the electromagnetic valve according to the first control signal and the second control signal. It is concluded that response time of the mass flow control apparatus of the present invention is shorten, and control quality is improved.

Abstract: An ultrasonic flow meter includes a conduit, a first ultrasonic transducer, a second ultrasonic transducer, and a controller. The first ultrasonic transducer is disposed at a first position about a first portion of the conduit to transmit a first ultrasonic signal and to receive a second ultrasonic signal. The second ultrasonic transducer is disposed at a second position about a second portion of the conduit that is spaced apart from the first position along a length of the conduit to transmit the second ultrasonic signal and to receive the first ultrasonic signal. The controller is configured to cross-correlate the first and second received ultrasonic signals and generate a resulting time-domain signal, analyze the resulting time-domain signal to determine a difference in transit time between the first and second received ultrasonic signals, and calculate a rate of flow of a fluid in the conduit based upon the determined difference.

Abstract: An ultrasonic flow meter includes a conduit, a first ultrasonic transducer, a second ultrasonic transducer, and a controller. The first ultrasonic transducer is disposed at a first position about a first portion of the conduit to transmit a first ultrasonic signal and to receive a second ultrasonic signal. The second ultrasonic transducer is disposed at a second position about a second portion of the conduit that is spaced apart from the first position along a length of the conduit to transmit the second ultrasonic signal and to receive the first ultrasonic signal. The controller is configured to cross-correlate the first and second received ultrasonic signals and generate a resulting time-domain signal, analyze the resulting time-domain signal to determine a difference in transit time between the first and second received ultrasonic signals, and calculate a rate of flow of a fluid in the conduit based upon the determined difference.

Abstract: A sensor that includes a first resistor, a second resistor, a first circuit, and a second circuit. The first and second resistors each has a resistance that varies in response to a change in a physical property. The first circuit is electrically coupled to the first resistor and sets the resistance of the first resistor. The second circuit is electrically coupled to the second resistor and adjusts the resistance of the second resistor to equal the resistance of the first resistor. A processing circuit may be coupled to the first and second circuits to measure a difference in an amount of energy provided by the first and second circuits to the first and second resistors, respectively.

Abstract: A sensor that includes a first resistor, a second resistor, a first circuit, and a second circuit. The first and second resistors each has a resistance that varies in response to a change in a physical property. The first circuit is electrically coupled to the first resistor and sets the resistance of the first resistor. The second circuit is electrically coupled to the second resistor and adjusts the resistance of the second resistor to equal the resistance of the first resistor. A processing circuit may be coupled to the first and second circuits to measure a difference in an amount of energy provided by the first and second circuits to the first and second resistors, respectively.

Abstract: A mass flow controller and purifier has a canister arranged at right angles to a flow path through the mass flow controller. The canister holds a contaminant scavenging material which a gas stream contacts as it flows to remove a contaminant such as water. A purified process gas stream is fed through a bypass of a mass flow meter. A portion of the gas is supplied to a mass flow sensor which generates a signal indicative of a rate of mass flow. The mass flow signal is amplified and the amplified mass flow signal is linearized in a linearizer. The linearized mass flow signal is fed to a comparator which compares the linearized mass flow signal with an error signal and provides an output signal indicative of a mass rate of flow through the mass flow meter. A valve is connected to the mass flow meter and is controlled by the mass flow meter signal to meter the gas.

Abstract: Apparatus which automatically measures the range and the lower and upper peak values of an unknown signal which varies periodically as a function of time. More specifically, an unknown time varying input signal is applied through a programmable attenuator to one input of a comparator. A direct current voltage which changes in equal incremental steps between predetermined levels is applied to the other input of the comparator. When coincidence occurs an output signal is developed by the comparator responsive thereto. The output signal thus developed is utilized to maintain the attenuator at the range level to which it was set when the coincidence was detected and also causes the reference level applied to the comparator to sequentially change in such a manner as to ascertain the lower and upper peak values of the applied signal.

Abstract: A voltage level display circuit for providing a display of the magnitude of the reference voltage level to a comparator circuit. A microprocessor is responsive to an input command signal to generate a digital reference voltage level which is converted by a digital to analog converter to an analog signal which is coupled to a reference voltage input of a comparator which compares the reference voltage level with an applied signal. A digital display is coupled to the output of the microprocessor to simultaneously provide a visual indication of the output of the microprocessor while generating the digital reference voltage signal.