Signaling device (control device) —an installation or device for giving a warning signal (for example, light, acoustic or other) that the value of the monitored parameter exceeds a given limit or is outside a specified range of values. [1] [2] As a discrete element, which under the influence of external physical factors abruptly changes its state belongs to the relay . [3] By the type of physical quantities to which non-electric relays react, they are divided into: mechanical , thermal , optical , magnetic , acoustic . [four]
Signaling devices along with sensors serve as primary converters in automatic signaling. The use of signaling devices (as opposed to sensors) makes it possible to give a signal that the monitored value is exceeded without additional signal processing in the secondary device. [five]
Emergency Indicator
To control the protection devices that protect the equipment from emergency conditions caused by failures of individual elements, unacceptable changes in the parameters of energy sources and the environment, and incorrect actions of the operating personnel, emergency situation indicators are used. [6]
In the emergency indicator, the current value of the monitored parameter perceived by the sensor is compared with the settings that are set by the controller and determine the permissible limit values. [6] The sensor perceives the values of the monitored parameter and converts them into a form convenient for further use. [6] The setting knob is used to set the limit value of the monitored parameter, upon reaching which the protection should operate. The limit value can be constant or changing according to a specific law. [6] The current value of the monitored parameter is compared with the setpoint and, depending on the magnitude of the difference between them, one of two signals is issued: “norm” or “deviation from the norm”. [6]
Notes
- ↑ Signaling device // Korneeva T.V. The explanatory dictionary of metrology, measurement technology and quality management. Key terms: about 7000 terms —M.: Rus., 1990
- ↑ Control device // TV Korneeva. The explanatory dictionary of metrology, measurement technology and quality management. Key terms: about 7000 terms —M.: Rus., 1990
- ↑ Relay // Korneeva T.V. The explanatory dictionary of metrology, measurement technology and quality management. Key terms: about 7000 terms —M.: Rus., 1990
- ↑ Relay element (relay) // Encyclopedia of modern technology. Industrial automation and industrial electronics. Volume 3 (Solution Error - Telemetry System Frequency) —M .: Soviet Encyclopedia, 1964
- ↑ Automatic alarm // Encyclopedia of modern technology. Industrial automation and industrial electronics. Volume 3 (Solution Error - Telemetry System Frequency) —M .: Soviet Encyclopedia, 1964
- ↑ 1 2 3 4 5 V. Litvak. Automatic emergency protection in control systems —M .: Energy, 1973