This International Standard specifies the analogue pneumatic signal used in industrialprocess measurement and control systems to transmit information between the elements of such systems. It is applicable to: a) pneumatic controllers; b) pneumatic transmitters and information transmission systems. This standard does not apply to analogue pneumatic signals used entirely within an element. The object of this standard is to establish: a) a standard operating pressure range for pneumatic information transmission systems; b) a standard air supply pressure (with limit values) for the operation of pneumatic controllers and transmitters, pneumatic information transmission systems, current-topressure transducers, and similar devices.