“Smart” is frequently used as a prefix to mean new and improved for technology and even consumer type products. The term “smart sensor” has been used for over three decades (Giachino, J. M., “Smart Sensors,” Sensors and Actuators, Vol 10, 1986). Earning the smart prefix, meant the sensor performed a function that could not be previously performed or was not previously economically viable.
It is important to recognize that a smart sensor has also been called an intelligent transducer with the terms also expressed as smart transducer or intelligent sensor.
In contrast to a dumb sensor, the smart means that the unit is more than a basic sensing (or transducing) element. The “more than” aspect was quite variable but ranged from signal conditioning to the ability to easily interface to a microcontroller unit (MCU) or other system components. Intelligence implies but did not necessarily require some computational capabilities. Semiconductor-based sensing (transducing) elements (including pressure and temperature) with their inherent capability to integrate additional circuit elements were the initial targets for increasing amount of sensing system functionality. However, the ease of adding an MCU into the form factor potentially made any sensor a smart sensor.
In 1993, the IEEE and the National Institute for Science and Technology (NIST) initiated activities that lead to the development of several IEEE 1451 standards that define different aspects of smart sensors (transducers). The application of these standards has found acceptance in a few areas.
Today, an internet search for “what is a smart sensor” provides many definitions and products called smart sensors. Software is an integral, and perhaps universal, part of a smart sensor as shown in the generic smart sensor model in Figure 1.
Figure 1. A possible smart sensor model. Source: Understanding Smart Sensors, Third Edition, Artech House.