In technology, the development and use of precise measuring, analysis, and control equipment. Among the oldest known instruments of measurement was the armillary sphere, an astronomical instrument used in ancient China and Greece. The compass was a striking advance in navigational instrumentation made about the 11th century. Theodolites made accurate determination of locations possible in the 18th century. Instrumentation developed rapidly in the Industrial Revolution. Manufacturing required precision instruments, such as the screw micrometer, which could measure 0.0001 in. (0.0025 mm). The industrial application of electricity required instruments to measure current, voltage, and resistance. Today most manufacturing processes rely on instrumentation for monitoring chemical, physical, and environmental properties. Instruments used in medicine and biomedical research are just as varied as those in industry. Seealso analysis.
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Instrumentation is the branch of science that deals with measurement and control in order to increase efficiency and safety in the workplace.
An instrument is a device placed in the field, or in the control room, to measure or manipulate flow, temperature, pressure and other variables in a process. Instruments include but are not limited to valves, transmitters, transducers, flame detectors and analyzers. Instruments send either pneumatic or electronic signals to controllers which manipulate final control elements (a valve) in order to get the process to a set point, usually decided by an operator.
Control instrumentation includes devices such as solenoids, Electrically Operated Valves, breakers, relays, etc. These devices are able to change a field parameter, and provide remote control capabilities.
Transmitters are devices which produce an analog signal, usually in the form of a 4-20 mA electrical current signal, although many other options are possible using voltage, frequency, or pressure. This signal can be used to directly control other instruments, or sent to a PLC, DCS, SCADA system or other type of computerized controller, where it can be interpreted into readable values, or used to control other devices and processes in the system.
Instrumentation plays a significant role in both gathering information from the field and changing the field parameters, and as such are a key part of control loops.
Instrumentation can be used to measure certain field parameters (physical values):
These measured values include:
In addition to measuring field parameters, instrumentation is also responsible for providing the ability to modify some field parameters.
Some examples include:
|Solenoid||Physical Location, Level|
|Circuit breaker||Voltage, Current|