A process pulsation diagnostic system comprising: a primary element for generating a differential pressure along a fluid flow; a sensor for sampling the differential pressure across the primary element; and a processor, wherein the processor is adapted to generate a pulsation diagnostic (P-D) by calculating a coefficient of the variation from the sampled differential pressure values, such that the pulsation diagnostic (P-D) is indicative of a degree of process pulsation in the fluid flow, characterised in that the processor is further adapted to either generate a square root error of the differential pressure, wherein the square root error is obtained from said calculated coefficient of variation and a lookup table or a simple piecewise linear model, wherein the lookup table and the simple piecewise linear model are a relationship between the square root error of the differential pressure and the coefficient of variation, or generate a normalized root mean square of the differential pressure, wherein the normalized root mean square is obtained from said coefficient of variation and a lookup table or a simple piecewise linear model, wherein the lookup table and the simple piecewise linear model are a relationship between the normalized root mean square of the differential pressure and the coefficient of variation, wherein the relationship between the square root error of the differential pressure and the coefficient of variation, and the relationship between the normalized root mean square of the differential pressure and the coefficient of variation are determined empirically based on simultaneous precision pressure and flow measurements in operating environments subject to high degrees of process pulsations. a primary element for generating a differential pressure along a fluid flow; a sensor for sampling the differential pressure across the primary element; and a processor, wherein the processor is adapted to generate a pulsation diagnostic (P-D) by calculating a coefficient of the variation from the sampled differential pressure values, such that the pulsation diagnostic (P-D) is indicative of a degree of process pulsation in the fluid flow, characterised in that the processor is further adapted to either generate a square root error of the differential pressure, wherein the square root error is obtained from said calculated coefficient of variation and a lookup table or a simple piecewise linear model, wherein the lookup table and the simple piecewise linear model are a relationship between the square root error of the differential pressure and the coefficient of variation, wherein the square root error is obtained from said calculated coefficient of variation and a lookup table or a simple piecewise linear model, wherein the lookup table and the simple piecewise linear model are a relationship between the square root error of the differential pressure and the coefficient of variation, or generate a normalized root mean square of the differential pressure, wherein the normalized root mean square is obtained from said coefficient of variation and a lookup table or a simple piecewise linear model, wherein the lookup table and the simple piecewise linear model are a relationship between the normalized root mean square of the differential pressure and the coefficient of variation, wherein the normalized root mean square is obtained from said coefficient of variation and a lookup table or a simple piecewise linear model, wherein the lookup table and the simple piecewise linear model are a relationship between the normalized root mean square of the differential pressure and the coefficient of variation, wherein the relationship between the square root error of the differential pressure and the coefficient of variation, and the relationship between the normalized root mean square of the differential pressure and the coefficient of variation are determined empirically based on simultaneous precision pressure and flow measurements in operating environments subject to high degrees of process pulsations.