(1) Plant. An inclusive term for sensing devices that measure, record, and control temperature, flow rate, thickness, pH, liquid level, and other process variables on a continuous basis. Some types, e.g., thickness gauges, utilize radioisotopes. Particularly sophisticated computerized instrumentation is required in petroleum refining and nuclear reactor control. (2) Laboratory. A broad range of analytical techniques and devices utilized in the many types of chromatography and spectroscopy. Significant advances in analytical instrumentation have been made in recent years, e.g., in liquid chromatography (HPLC). A notable event in this field is the annual Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy. (3) General. Of special significance for both laboratory and process control is the introduction of fiber optical devices that can transmit signals from many remote locations. They are particularly useful in analyzing samples of radioactive chemicals and other hazardous materials. They are also used in high-temperature thermometry and dosimetry.See Fiber, Optical.
