This paper presents the design and development of a generic model of an autonomous sensor (independent, self-reliant, self-sufficient). The model accommodates behaviors common to most sensors. The term behavior refers to characteristics of the sensor as well as those of the measurand. The autonomous sensor is a sensor that not only interprets the acquired data in an intelligent manner but is also capable of using this data base along with its knowledge base to interpret its own behaviors. In other words, The autonomous sensor is capable of learning and thereby evolving with time so as to keep itself in as perfect an operating condition as is possible. The sensor's data base is defined as the quantitative data it senses as well as qualitative data it interprets. It's knowledge base is defined as the rules that allow maintenance of the truth and integrity of the system and also allow for model learning, i.e., modification of existing rules and addition of new rules using machine learning techniques. This paper presents an initial attempt to separate the different processes that would lead to a formalized theory so as to give any sensor total autonomy. The objective of the model is to allow the sensor to operate in an 'intelligent' manner regardless of the control system in which it may be used. A simulated autonomous thermistor has been instantiated as an example. The model was tested to evaluate its correct operation and level of autonomy.