Recently, the Guangdong Provincial Quality Supervision Bureau announced the results of the supervision and inspection of seven kinds of products in the production area of ​​the province in the second quarter of this year, the batch pass rate was 76.3%; the qualified rate of lamps increased by 20.6 percentage points compared with last year, the audio power The pass rate of the amplifier is only 39.7%, which seriously downgraded the province's regular supervision and inspection pass rate.
This time, a total of 1076 batches of 982 manufacturers of lamps, daily-use ceramics, clothing, audio power amplifiers, shoes, PVC construction pipes and adhesives were sampled. From the results of the spot check, the qualified rate of daily-use ceramics and PVC building pipe products is relatively high; the qualification rate of lamps, garments, shoes and adhesives is relatively low, and the quality problems of audio power amplifiers are more prominent.
This time, a total of 340 batches of lighting products were produced from 334 production enterprises in 7 cities including Guangzhou City and Zhongshan City. The qualified rate of sample sampling batches was 74.4%, which was greatly improved compared with last year, reflecting the improvement of the quality of lighting products in the province. . The unqualified items mainly include:
First, the power supply current harmonics, power supply terminal disturbance voltage, and insertion loss items are unqualified. There were 49 batches of unqualified items in this spot check. The main reason for the failure is that some companies know electromagnetic compatibility, but they do not know how to design a circuit that conforms to the standard, or they are limited to devices that are not tested by themselves.
Second, the protection against electric shock is unqualified. There were 35 batches of unqualified items in this spot check. The main reason for the failure is the use of unqualified lamp holder products, and the procurement of products is not strict.
Third, the heat-resistant and refractory projects failed. There were 32 batches of unqualified items in this spot check. The main reason for the failure is the use of inferior or low-temperature insulation and fire-resistant parts, and the procurement and daily inspection are not strict.
This time, 63 batches of audio power amplifier products from 63 manufacturers were sampled. After testing, 38 batches were rejected. Although the product sampling rate of 32.7% was slightly improved compared with last year, the quality problem is still serious. The unqualified items in this spot check are mainly:
The first is a safety test. There were 32 batches of unqualified samples in this spot check, and the unqualified rate was as high as 50.8%. Mainly manifested in the signs and instructions for use, structural requirements for protection against electric shock, electric shock hazards under normal working conditions, clearances and creepage distances do not meet the standard requirements. The main reason for the disqualification is that the production enterprises do not understand the standards and are not marked according to national regulations. In addition, the circuit structure design is not reasonable.
The second is the normal temperature electrical performance test. There were 26 batches of unqualified samples in this spot check, and the failure rate was 41.3%. The electrical performance of the audio power amplifier directly affects the true degree of its restored sound. The main items causing the failure are the distortion-limited output power, the effective frequency range of the gain limit, the total harmonic distortion, and the signal-to-noise ratio. The main reason for the failure is that the product specification of the manufacturer indicates that the technical indicators are too high, and the actual electrical performance of the product does not meet the express technical requirements of the product. There are many reasons for this. On the one hand, the manufacturer does not have enough production and testing equipment or is equipped with the necessary testing and technical personnel, and does not know what level of performance indicators can be achieved. On the other hand, the manufacturer intentionally Improve your product metrics to deceive ordinary consumers who don't understand the true performance of the product.
The third is electromagnetic compatibility testing. There were 14 batches of unqualified samples in this spot check. Products with unacceptable electromagnetic compatibility will cause the electromagnetic environment around them to deteriorate, so that the surrounding equipment cannot be in normal working condition. For example, interference with television viewing, radio listening; data loss during digital system and data transmission; failure of medical electronic equipment; malfunction of civil aviation navigation system; accidental detonation of detonating device; failure of industrial process control function, etc. . The main reason for the failure is that the company does not pay attention to the electromagnetic compatibility of the products, does not produce according to the requirements of the qualified products in the 3C certification, arbitrarily change the circuit wiring, change the key component models and suppliers, and even the specifications of the components or The entire key components are replaced, or the necessary electromagnetic compatibility measures are completely removed in production. All of the above changes have completely changed the electromagnetic compatibility of the product, making the product inconsistent with the product in the certification process inconsistent, resulting in unqualified spot checks.
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