Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: A gas sensor for sensing the presence of a gas includes an IR source, a microphone, a reference gas substantially similar to the gas to be detected, a reference body defining a reference chamber therein, the reference chamber having a pressure port coupled to the microphone, and a broad-band optical window through which at least IR wavelengths corresponding to absorption peaks of the predetermined gas may pass. The window is disposed between the IR source and reference chamber. The reference gas is contained within the reference chamber between the optical window and the microphone. The sensor can be included in a hand-held gas detection instrument having power supply, an outer shell, a circuit board assembly including sensor circuitry, a suction pump, actuation controls and status indicators. A probe defining a lumen therethrough supplies the sample gas.

Abstract: Methods automatic process control of biasing and testing a heated-electrode refrigerant sensor for use in a refrigerant detector. An unbiased sensor may be mounted in a manufacturing station, and while mounted may be biased by applying current to electrically heat the sensor and by applying a voltage potential between the sensor's anode and cathode, thereby generating a bias current at the cathode, and after the sensor is at least partially biased, the bias current is used to electrically test the sensor's construction. If the temperature of the sensor is held constant at a bias temperature, the acceptability of the sensor may be determined based on the time that elapses before the bias current decreases from an initial value to a threshold value, or determined based on the noise present on a signal which is representative of an operating condition other than the bias current magnitude.

Abstract: A gas detector, as useful for conducting refrigerant fluid leak detection, having a housing, a probe and a sample flow path assembly capable of providing a sample air flow rate to a sensing device in excess of 300 SCCM. The sample flow path assembly also provides the gas detector with a short signal path between the sensing device and a printed circuit board within the housing, an efficient sample path, and ready access to and easy replacement of the sensing device as well as of the probe, making the gas detector generally more reliable and cost effective. The sample path assembly requires a simple method of construction and sensing device replacement thereby reducing the difficulty and the time required for manufacturing the sample flow path assembly and, ultimately, reducing the cost of manufacturing the electronic gas leak detector.

Abstract: Methods and apparatuses are disclosed for automatic process control of firing and biasing a heated-electrode refrigerant sensor for use in a refrigerant detector. An unfired sensor may be mounted in a manufacturing station, and while remaining mounted may be electrically heated by applying current and adjustably controlling the amount of power to gradually increase the temperature. Once the sensor reaches a suitable temperature, the sensor is fired, and while the temperature of the sensor is elevated, the sensor is biased. The temperature increase may take place at a first rate until substantially all the moisture is removed, and then at a second rate. Upon reaching the bias temperature, the temperature may be held generally constant for a first period of time before increasing to a second bias temperature for a second period of time.

Abstract: A gas detector for sensing the presence of at least one predetermined gas is operative in conjunction with a electrical power source and includes a detection circuit, a temperature controller, and a electrical current controller, wherein the detection circuit includes a sensing device having first and second electrodes, the first electrode being connected to the power source for heating the first electrode, the temperature controller is operatively connectable to the detection circuit for maintaining a temperature of the first electrode at a predetermined magnitude, and the current controller is operatively connectable to the detection circuit for maintaining a current in the second electrode at a predetermined magnitude.

Abstract: A gas detector having a sample flow path assembly capable of providing a sample air flow rate to a sensing device in excess of about 300 SCCM. The sample flow path assembly also provides the gas detector with a short signal path between the sensing device and a printed circuit board, an efficient sample path, and ready access to and easy replacement of the sensing device as well as easy replacement of the probe, making the gas detector generally more reliable and cost effective. The sample path assembly requires a simple method of construction and sensing device replacement thereby reducing the difficulty and the time required for manufacturing the sample flow path assembly and, ultimately, reducing the cost of manufacturing the leak detector.

Abstract: A gas detector having a sample flow path assembly capable of providing a sample air flow rate to a sensing device in excess of about 300 SCCM. The sample flow path assembly also provides the gas detector with a short signal path between the sensing device and a printed circuit board, an efficient sample path, and ready access to and easy replacement of the sensing device as well as easy replacement of the probe, making the gas detector generally more reliable and cost effective. The sample path assembly requires a simple method of construction and sensing device replacement thereby reducing the difficulty and the time required for manufacturing the sample flow path assembly and, ultimately, reducing the cost of manufacturing the leak detector.

Abstract: A gas detector having a sample flow path assembly capable of providing a sample air flow rate to a sensing device in excess of about 300 SCCM. The sample flow path assembly also provides the gas detector with a short signal path between the sensing device and a printed circuit board, an efficient sample path, and ready access to and easy replacement of the sensing device as well as easy replacement of the probe, making the gas detector generally more reliable and cost effective. The sample path assembly requires a simple method of construction and sensing device replacement thereby reducing the difficulty and the time required for manufacturing the sample flow path assembly and, ultimately, reducing the cost of manufacturing the leak detector.

Abstract: Methods and apparatuses are disclosed for automatic process control of firing and biasing a heated-electrode refrigerant sensor for use in a refrigerant detector. An unfired sensor may be mounted in a manufacturing station, and while remaining mounted may be electrically heated by applying current and adjustably controlling the amount of power to gradually increase the temperature. Once the sensor reaches a suitable temperature, the sensor is fired, and while the temperature of the sensor is elevated, the sensor is biased. The temperature increase may take place at a first rate until substantially all the moisture is removed, and then at a second rate. Upon reaching the bias temperature, the temperature may be held generally constant for a first period of time before increasing to a second bias temperature for a second period of time.

Abstract: Methods and apparatuses are disclosed for automatic process control of biasing and testing a heated-electrode refrigerant sensor for use in a refrigerant detector. An unbiased sensor may be mounted in a manufacturing station, and while mounted may be biased by applying current to electrically heat the sensor and by applying a voltage potential between the sensor's anode and cathode, thereby generating a bias current at the cathode, and after the sensor is at least partially biased, the bias current is used to electrically test the sensor's construction. If the temperature of the sensor is held constant at a bias temperature, the acceptability of the sensor may be determined based on the time that elapses before the bias current decreases from an initial value to a threshold value, or determined based on the noise present on a signal which is representative of an operating condition other than the bias current magnitude.

Abstract: A gas detector for sensing the presence of at least one predetermined gas is operative in conjunction with a power source and includes a detection circuit, a temperature controller, and a current controller, wherein the detection circuit includes a sensing device having first and second electrodes, the first electrode being connected to the power source for heating the first electrode, the temperature controller is operatively connectable to the detection circuit for maintaining a temperature of the first electrode at a predetermined magnitude, and the current controller is operatively connectable to the detection circuit for maintaining a current in the second electrode at a predetermined magnitude.