This part of GB/T 4909 specifies the measurement tools, sample preparation, measurement steps, test results, and evaluation for bare wire size measurement tests. This section is applicable to measuring the overall dimensions, fillet radius, pitch diameter ratio, and cross-sectional area of various circular, rectangular, irregular, and stranded conductors. When there are higher requirements for the measurement accuracy of external dimensions, the corresponding product standards shall prevail. This part should be used in conjunction with GB/T 4909.1-2009. 2 Normative References: The clauses in the following documents are referred to in this part of GB/T 4909 and become the clauses of this part. For dated reference documents, all subsequent amendments (excluding corrected content) or revisions do not apply to this section. However, parties to agreements based on this section are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest version applies to this section. GB/T 1216-2004 Outside Diameter Micrometers (DIN 683-1999, MOD) GB/T 3048.2-2007 Test Methods for Electrical Properties of Electric Wires and Cables, Part 2: Electrical Resistivity Testing of Metallic Materials (IEC 60498:1974, MOD) GB/T 4909.1-2009 Test Methods for Bare Wires, Part 1: General GB/T 8061-2004 Levered Micrometers GB/T 21389-2008 Vernier, Band Gauge, and Digital Calipers JB/T 8788-1998 Feeler Gauges
Function of testing report:
1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report
2. Online e-commerce platform entry: Quality inspection report recognized by major e-commerce platforms 3. Used as a sales report: issuing legally effective testing reports to make consumers more confident 4. Papers and research: Provide professional personalized testing needs 5. Judicial services: providing scientific, fair, and accurate testing data 6. Industrial problem diagnosis: Verify the troubleshooting and correction of industrial production problemsBaijian and testing process:
1. Telephone communication and confirmation of requirements
2. Recommend solutions and confirm quotations 3. Mail samples and arrange testing 4. Progress tracking and result feedback 5. Provide reports and after-sales service 6. If urgent or priority processing is requiredTesting and testing characteristics:
1. The testing industry is fully covered, meeting different testing needs
2. Fully cover the laboratory and allocate localized testing nearby3. Engineers provide one-on-one services to make testing more accurate
4. Free initial testing, with no testing fees charged
5. Self service order delivery for free on-site sampling
6. Short cycle, low cost, and attentive service 7. Possess authoritative qualifications such as CMA, CNAS, CAL, etc 8. The testing report is authoritative and effective, and is generally used in China