Criteria for selecting pneumatic and electric instruments in engineering design

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This post was last edited by crjgood on 2010-7-6 08:37. In engineering design, whether to use pneumatic or electric instruments depends on their respective advantages; a comprehensive consideration and analysis based on the specific conditions of the installation are necessary. The following points can be used as a reference when making a choice: 1. Degree of centralized operation ； 2. Is it operated in conjunction with a computer? ； 3. Require fast response time ； 4. Cost-effectiveness ； 5. Reliability and operation/maintenance ； 6. Safety (explosion protection, power outages, gas supply failures, etc.) ； 7. Environmental conditions and transmission distance. Generally speaking, the following conditions indicate that it is appropriate to use pneumatic instruments: 1. The distance between the transmitter and the display/regulation instrument is short; usually, it is better not to exceed 150 meters ； 2. The process materials are flammable and explosive substances, and the environment has a high relative humidity ； 3. Require low investment in instruments ； 4. Generally, small and medium-sized enterprises require easy maintenance and economic reliability ； 5. In large installations dominated by electric instruments, there are some on-site control circuits that do not require integration into the central control room for centralized operation. The following conditions indicate that it is advisable to use electric meters: 1. When the distance between the transmitter and the display/control unit exceeds 150 meters ； 2. Large enterprises require a centrally controlled system with a high degree of centralized management ； 3. Objects for which a computer is used for control and management ； 4. Applications that require fast response times and involve complex information processing and calculations. In modern production facilities, they are selected and combined based on their respective characteristics. The above are the statements from the Design Manual; everyone can share their own practical experience from the field, express their opinions, discuss together, and work towards improvement!