Integral temperature and liquid level sensor and control

A process control method for receiving an output from an integral temperature and liquid level sensor as an input to the process control method, the integral temperature and liquid level sensor including an integral temperature sensor within a housing portion and a liquid level sensor including a conductive housing portion of the integral temperature and liquid level sensor, the steps of the method comprising:

• providing an integral temperature and liquid level sensor, the integral temperature and liquid level sensor including a housing having conductive portions and a temperature sensor within the housing;
• generating a temperature information input signal based upon a fluid temperature sensed by the temperature sensor within the housing;
• generating a liquid level signal based upon immersion of at least a portion of the conductive portion of the housing of the integral temperature and liquid level sensor in a liquid;
• providing a power source for the integral temperature and liquid level sensor means and an associated process controller;
• providing the associated process controller with a temperature set point;
• transmitting the temperature and liquid level signals from the integral temperature and liquid level sensor to the process controller;
• processing the temperature and liquid level signals;
• energizing a heater when the temperature and liquid level signals from the integral temperature and liquid level sensor to the process controller corresponds to a liquid temperature below the temperature set point and a liquid level sufficient to close a circuit including the conductive portion of the housing of the integral temperature and liquid level sensor;
• and
• de-energizing the heater when either the temperature and liquid level signals from the integral temperature and liquid level sensor means corresponds to a liquid temperature above the provided temperature set point, or the liquid level signal from the integral temperature and liquid level sensor corresponds to a liquid level sufficiently below the conductive portion of the housing of the integral temperature and liquid level sensor so that the circuit including the conductive portion of the housing of the integral temperature and liquid level sensor is open.