For the uninitiated, sensors (or sensing elements as they're sometimes called) are devices that allow a user to measure the value of some physical condition of interest using the inherent physical properties of the sensor.
That's quite a mouthful for a pretty simple concept, namely monitoring the behaviour of one (relatively) easy-to-observe parameter to deduce the value of another difficult-to-observe parameter.
An example of a very familiar non-electronic temperature sensor is the mercury bulb thermometer, in which a column of mercury contracts or expands in response to the temperature of the material to which it's exposed.
In this case, the physical condition that we're measuring is the temperature of the material in which the thermometer is inserted, and the inherent physical property of the sensor that we use for measurement is the height of the mercury in the thermometer.
So what kinds of parameters can we measure with sensors? The answer is quite a lot, actually, with the limiting factor generally being our imaginations. Probably the most widely measured parameter is temperature, but other applications include pressure, acceleration, humidity, position, pH, and literally thousands more.
What makes sensors so useful, though, is not just their ability to accurately measure a wide range of parameters but that the sensors can perform those measurements under environmental conditions in which human involvement is simply impossible.
Whether it's measuring the temperature of molten steel at the center of a blast furnace or monitoring the ocean current thousands of feet below the surface, sensors provide the accurate information that allows us to monitor and control all sorts of important processes.
At first glance, it might seem that sensors fall in the same category as a comfortable sweatshirt, nice to have but not particularly exciting. In this case, such a first impression would be dead wrong.
To put things in perspective, in 2005 there were an estimated 6.4 billion people living on the planet. Coincidentally, the market for industrial sensors in the United States alone in 2005 was estimated to be $6.4 billion, and $40 billion worldwide.
There are far more sensors in the world than humans, they're called upon to do tasks that range from the mundane to the cutting edges of science, and people are willing to pay for the value that sensors bring to the table. That's a powerful and profitable confluence of need, technical challenge, and economic opportunity, and into the fray has stepped a new class of devices that is bringing disruptive change to the sensing world: intelligent sensors.
Intelligent Sensors are a new class of electronic sensing device that's literally revolutionizing the way we gather data from the world around us, how we extract useful information from that data and, finally, how we use our newfound information to perform all sorts of operations faster, more accurately, safer, and less expensively than ever before.
Even better, we can leverage the power of individual intelligent sensors by communicating their information to other intelligent sensors or to other systems, allowing us to accomplish tasks that weren't possible before and creating incredible advancements in a wide variety of applications.