This part of ISO 7278 specifies the procedures and conditions of use to be observed if pulse interpolation is used in conjunction with a pipe prover and a turbine meter or displacement meter of good intra-rotational linearity to improve the discrimination of proving. It does not apply to other types of prover or other types of meter, to which these or other techniques of pulse interpolation may apply. It does not necessarily apply to meters fitted with accessories which superimpose a cyclic variation on the output of the meter such as temperature compensators or calibrators. This part of ISO 7278 describes the three methods most commonly used and their conditions of use. It also describes the equipment and test procedures for checking that the pulse interpolation system is operating satisfactorily.