Editorial: Extra(sensor)y Control On The Way
The National Science Foundation (NSF; www.nsf.gov) has supported basic research on sensors for decades and now has a foundation-wide Sensors and Sensor Networks Program. The program began in 2003 with first-year funding of $47 million. NSF-funded researchers are pursuing new technology together with researchers supported by other agencies, universities and by industry.
Sensor technology is undergoing a rapid transformation in at least three different directions: sensors are becoming smaller, smarter and more mobile. Emerging technologies can decrease the size, weight and cost of sensors and sensor arrays significantly and increase their spatial and temporal resolution and accuracy. Large numbers of sensors may be integrated into systems to improve performance and lifetime and decrease life-cycle costs. Advances in fields such as nanotechnology and micro electro-mechanical systems (MEMS) have led to ultracompact versions of traditional sensors and have inspired the creation of sensors based on entirely new principles. The exponentially increasing power of microelectronics has made it possible to create sensors with built-in intelligence. Today's sensors can store and process data on the spot, selecting only the most relevant and critical items to report, and wireless networking technologies allow sensors to send back data from remote locations, or even while they're in motion.
Information extraction can involve detection of events or objects of interest, estimation of key parameters, and human-in-the-loop or closed-loop adaptive feedback. Arrays of ultralow-power wireless nodes can be incorporated into high-bandwidth reconfigurable networks with high-speed connectivity to processing centers for decision and responsive action.
Sensing principles include mechanical, chemical, thermal, electrical, chromatographic, magnetic, biological, fluidic, optical, acoustic, ultrasonic and mass sensing. Sensors also may be exposed to hostile environments, and they may be incorporated in mobile robotic systems, stationary platforms or into manufacturing systems. Sensors may be used in environments that involve high temperatures, high pressure, high vibration, high noise and corrosive chemicals. Sensing and control technology has the potential for significant advances with profound benefits for industry and society as a whole.
Why is this significant for the thermal processing industry? Consider the heat treating industry. The quality of heat treating (including induction heat treating) processes is significantly influenced by many process variables including furnace and load temperature, loading, atmosphere potential, carbon flux, gas flow, furnace pressure, quench severity and others, which are controlled using sensors and analyzers, such as thermocouples, oxygen probes and pressure gages, etc. For induction heat treating, sensors typically are used to measure such variables as induction heating power, part rotation, scan speed, quench flow, quench temperature, water temperature, generator voltage, and part temperature. It follows that improved sensors will continually increase the reliability of heat treatment processes due to improved process control.