Why 4 - 20 mA? ( in Hindi ) 

This video describes why series current loop signal 4 to 20 mA is used as standard field instrument Analog Signal vs 0 to 20 mA, and 0 to 10 V across industries and the basic fundamentals behind making it standard.@dineshdiwani
4 to 20 mA is mostly used analog signal for transmission from the transmitter to the controller or to PLC/DCS. This signal was among the other available signal such as 0 to 20 mA, 10 to 50 mA, 0 to 10 VDC, and 0 to 5 VDC which emerged when electronics were replacing pneumatic instrumentation. But 4-20 mA has some advantages over other systems This video tells why 4-20 mA loop is adapted over others and how it works. Any queries or doubts may be posted in the comment section.
ref links
instrumentationtools.com/why-....
instrumentationapplication.co...
www.predig.com/indicatorpage/...
#analog #analogcommunication #instrumentation

Наука