Liquid pumps and pumps units. Noise test code. Grades 2 and 3 of accuracy has-digital Carbon fibre reinforced resin panels

Carbon fibre reinforced resin panels are extremely strong and light fibre-reinforced plastics that contain carbon fibres

and for solid insulation in general

and various fluids

BS EN 62058-21 is the 21st part of the IEC 62058 series that  specifies particular requirements for acceptance inspection of newly manufactured direct connected or transformer operated electromechanical meters for active energy (classes

Liquid pumps and pumps units. Noise test code. Grades 2 and 3 of accuracy has-digital Carbon fibre reinforced resin panels1 Scope This document specifies all the information necessary to carry out efficiently and under standardized conditions the determination, declaration, and verification of the airborne noise emission of liquid pumps or pump units (see 4. 1). It specifies the noise measurement methods and the operating and mounting conditions that shall be used for the test. Noise emission characteristics include emission sound pressure levels at specified positions