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Standard number: JB9970-1999. This standard is a revision of ZB J62 006.4—87 \"Noise limits for forging machinery – Noise limits for die shear machines and combined die shear machines\". This standard is essentially consistent with the technical content of ZB J62 006.4—87, with only reformatting carried out in accordance with relevant regulations. This standard has been in effect since January 1, 2000. This standard replaces ZB J62 006.4—87 as of the date of its implementation. Appendix A of this standard is an appendix to the standard. This standard was proposed and taken under responsibility by the National Standardization Technical Committee for Forging Machinery. The entity responsible for drafting this standard is Heilongjiang Forging Machine Tool Factory. This standard was first published in April 1987. 1 Scope This standard specifies the noise limit values for sound power level and sound pressure level of punching shear machines and combined punching-shearing machines. This standard applies to punching shear machines and combined punching and shearing machines. 2 Referenced Standards The provisions contained in the following standards become part of this standard by being referenced herein. At the time of publication of this standard, all versions shown are valid. All standards will be revised, and those using this standard should consider the possibility of using the latest versions of the following standards. JB/T 3623—1984 Pressing Machinery – Methods for Noise Measurement 3 Noise limits for die shear machines 3.1 The A-weighted sound power level LWA of a die shear machine during continuous idling operation shall not exceed 94 dB(A). 3.2 When the die shear machine is running idly continuously, the noise A-weighted sound pressure level LpA at the specified location shall not exceed 80 dB(A). 4 Noise limits for combined punching and shearing machines 4.1 The A-weighted sound power level LWA of a combined punching and shearing machine during continuous idling operation shall not exceed the values specified in Table 1. 4.2 When the combined punching and shearing machine is running idly continuously, the A-weighted sound pressure level LpA at the specified location shall not exceed the values specified in Table 2. 5 Measurement Methods The measurement methods specified in this standard shall comply with the provisions of JB/T 3623. 6 Instructions for Use The instructions for using this standard are provided in Appendix A (the appendix to the standard). Appendix A (Standard Appendix) Instructions for Using This Standard A1 For all prototype units of newly designed or improved products, as well as small batches of newly produced items; for the first batches of punching and shearing machines or combined punching and shearing machines manufactured after changes in processes or materials; and for such machines used for quality grading and performance testing, it is necessary to measure the noise sound pressure level. It is recommended to also measure the noise sound power level. For A2 standard mass-produced die shears and combined die shear machines, only the noise sound pressure level needs to be measured during factory inspection. This post was last edited by hw197358 on 2009-2-24 19:04.]