ISO 4392-3:1993

Describes a method of determining the low-speed characteristics of positive-displacement rotary fluid power motors under constand flow and constant torque conditions. The method involves testing at slow speeds, which may generate frequencies having a significant influence upon the steady continuous torque output of the motor and affect the system to which the motor would be connected. The accuracy of measurement is divided into three classes, A, B and C, which are explained in annex A.