Defines a method for determining a rating of the source flow ripple, source impedance and pressure ripple levels produced by positive-displacement hydraulic motors, as well as bi-directional motors. Ratings are attained as: source flow ripple amplitude in cubic meters per second and source impedance amplitude in newton seconds per metre to the power of 5 and phase in degrees, over 10 individual harmonics of motoring frequency; anechoic pressure ripple amplitude in pascals and blocked acoustic pressure ripple amplitude in pascals, both over 10 harmonics of motoring frequency; overall root mean square anechoic pressure ripple and overall root mean square blocked acoustic pressure ripple in pascals. All types of positive-displacement motors in the 50 Hz to 400 Hz frequency range are covered.

This part of ISO 10767 specifies a procedure for the determination of a rating of the source flow ripple, source impedance and pressure ripple levels generated by positive-displacement hydraulic motors, including bi-directional motors. Ratings are obtained as the following: the source flow ripple amplitude, in cubic metres per second, over ten individual harmonics of motoring frequency; the source impedance amplitude, in newton seconds per metre to the power of five [(N·s)/m5], and phase, in degrees, over ten individual harmonics of motoring frequency; the anechoic pressure ripple amplitude, in pascals, over ten harmonics of motoring frequency; the overall root mean square (r.m.s.) anechoic pressure ripple, in pascals; the blocked acoustic pressure ripple amplitude, in pascals, over ten harmonics of motoring frequency; the overall root mean square (r.m.s.) blocked acoustic pressure ripple, in pascals. This part of ISO 10767 is applicable to all types of positive-displacement motor operating under steady-state conditions, irrespective of size, provided that the motoring frequency is in the range from 50 Hz to 400 Hz.