This part of ISO 7440 specifies the flow-measuring System, including the fixture, to be used for flow- testing the Single hole orifice plates used in an orifice plate type nozzle and holder assembly (de- scribed in ISO 7440-1) which are intended for testing and setting diese1 fuel injection Pumps on test benches. The flow-measuring System and fixture described in this part of ISO 7440 ensure accurate flow-testing of the entire range of orifices from 0,4 mm to 0,8 mm diameter as specified in ISO 7440-1. lt is intended primarily for use by the manufacturers of Single hole orifice plates.