I would like to ask you about the connection of capacitors.
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Often when the signal is unstable or interfered with in the analog input (4-20ma), a capacitor needs to be connected to the terminal block. Could you please tell me the function and principle of connecting the capacitor? It would be better if you could post the drawings.
The capacitor plays a filtering role, and the purpose is to filter out the clutter in the line. However, generally display instruments and DCS systems have filter circuits.； It is not necessary to add a capacitor to the terminal unless it is damaged.
But sometimes the display instrument and DCS system will add capacitors when they are not damaged, in order to prevent interference. I don’t know why.