This standard specifies the classification, requirements, test methods, defect classification and type test qualification principles and markings of music piano movements, instructions for use, etc. This standard applies to music piano movements that use clockwork, micromotor or manual as the power source.
QB/T 4889-2016 Referenced Document
GB/T 3768 Acoustics—Determination of sound power levels and sound energy levels of noise sources using sound pressure—Survey method using an enveloping measurement surface over a reflecting plane*， 2017-12-29 Update
QB/T 4889-2016 history
2016QB/T 4889-2016 Technical request for musical movement