Methods and apparatuses for automatic process control for biasing and testing heated electrode refrigerant sensors

A manufacturing station for manufacturing a heated-electrode refrigerant sensor for use in a refrigerant detector, the sensor having a cathode and an anode, the manufacturing station comprising:

• mounting means for supporting an unbiased sensor;
• means for biasing the sensor, while the sensor remains supported by the mounting means, by applying current through the sensor to electrically heat the sensor and by applying a voltage potential between the anode and the cathode, thereby generating a bias current at the cathode;
• and
• means for utilizing the bias current to electrically test the construction of the sensor after the sensor is at least partially biased, while the sensor remains supported by the mounting means.

A manufacturing station for manufacturing a heated-electrode refrigerant sensor for use in a refrigerant detector, the sensor having a cathode and an anode, the manufacturing station comprising:

• a socket for supporting an unbiased sensor;
• a current source and a voltage source for biasing the sensor, while the sensor remains supported by the socket, by applying current through the sensor to electrically heat the sensor and by applying a voltage potential between the anode and the cathode, thereby generating a bias current at the cathode;
• and
• a bias current monitor for utilizing the bias current to electrically test the construction of the sensor after the sensor is at least partially biased, while the sensor remains supported by the socket.

A method of manufacturing a heated-electrode refrigerant sensor for use in a refrigerant detector, comprising the steps of:

• generating a bias current in the sensor;
• setting the temperature of the sensor to a bias temperature;
• monitoring the bias current while holding the temperature essentially constant at the bias temperature;
• and
• determining the acceptability of the sensor on the basis of the amount of time that elapses before the magnitude of the bias current decreases from an initial value to a predetermined threshold value.

A manufacturing station for manufacturing a heated-electrode refrigerant sensor for use in a refrigerant detector, comprising:

• means for generating a bias current in the sensor;
• means for setting the temperature of the sensor to a bias temperature;
• means for monitoring the bias current while holding the temperature essentially constant at the bias temperature;
• and
• means for determining the acceptability of the sensor on the basis of the amount of time that elapses before the magnitude of the bias current decreases from an initial value to a predetermined threshold value.

A manufacturing station for manufacturing a heated-electrode refrigerant sensor for use in a refrigerant detector, comprising:

• a current source and a voltage source for generating a bias current in the sensor;
• a temperature controller for holding the temperature of the sensor essentially constant at a bias temperature;
• a bias current monitor for monitoring the bias current, the bias current monitor operating at the same time as the temperature controller;
• and
• a timing device for measuring the amount of time that elapses before the magnitude of the bias current decreases from an initial value to a predetermined threshold value, wherein the acceptability of the sensor may be determined on the basis of the amount of time.

A method of testing a heated-electrode refrigerant sensor, comprising the steps of:

• generating a bias current in the sensor;
• generating a first signal at least partially representative of the magnitude of the bias current, the magnitude of the bias current being a first operating condition;
• generating a second signal at least partially representative of a second operating condition;
• maintaining the magnitude of the bias current at a generally constant level on the basis of the first signal;
• and
• monitoring the second signal for noise.

A manufacturing station for testing a heated-electrode refrigerant sensor, comprising:

• means for generating a bias current in the sensor;
• means for generating a first signal at least partially representative of the magnitude of the bias current, the magnitude of the bias current being a first operating condition;
• means for generating a second signal at least partially representative of a second operating condition;
• means for maintaining the magnitude of the bias current at a generally constant level on the basis of the first signal;
• and
• means for monitoring the second signal for noise.

A manufacturing station for testing a heated-electrode refrigerant sensor, comprising:

• a current source and a voltage source for generating a bias current in the sensor;
• a first signal generator for generating a signal at least partially representative of the magnitude of the bias current, the magnitude of the bias current being a first operating condition;
• a second signal generator for generating a second signal at least partially representative of a second operating condition;
• a bias current controller for maintaining the magnitude of the bias current at a generally constant level on the basis of the first signal;
• and
• a noise detection device for monitoring the second signal for noise.