If i use 5 mA instead of 4 mA what will happen?

For input: The range of input of PLC and DCS mostly using a 4-20 mA. If we use a 5 mA there shall be deviation of reading of tranmitter in  PLC or DCS.

For output also have problem since most of final control element such as control valve uses a 4-20 mA. If we use a 5mA, there will be a deviation of output due to this.

Indication in Control Room will be (1/16)*100%. For valve, depends by characteristics (linear, equal percentage, quick opening). Valve is moving from fail position (open or close).