Semiconductor sensors

In all natural or artificial organs, the cause-effect relationship can take the form of a succession of sensing, processing and acting organs. For the sensor, which transforms "external" information into a quantity compatible with the processing organ, we use the definition given below.

We'll call a sensor a minimal subset of any object that transforms information represented by a physical quantity of a certain dimension (L ^x , M ^y , T ^u , I ^v ) into a physical quantity of a different dimension (L ^x , M ^y' , T ^u' , I ^v' ), or no dimension at all.

For example, as defined above :

• The sensors are :

• a spring-loaded dynamometer transforming a force (MLT ^-2 ) into a displacement (L),

• a motor transforming a current (I) into mechanical torque (ML ² T ^-2 );

• Not sensors:

• a lever transforming an angle into an angle ;

• an electrical transformer.

Clearly, the functionality of a sensor will be defined at least by the dimensions of the input and output quantities, and by the relationship between these quantities.

Note: often, only the input variable is given (e.g. temperature, acceleration or pressure sensor), because the output variable is considered to be defined by the context of use. Given the preponderance of electronic processing, this is usually an electrical quantity.