Radio Frequency Testing

1. Introduction to Certification

UL is the abbreviation of Underwriter Laboratories Inc. UL Safety Testing Institute is the most authoritative in the United States and the largest non-governmental organization engaged in safety testing and appraisal in the world. UL certification is a non-compulsory certification in the United States, mainly for testing and certification of product safety performance. The entire U.S. market pays great attention to product safety; more than 40,000 administrative districts in the federal, state, county, and municipal governments of the United States all recognize the UL certification mark; Amazon USA also requires some products to have UL certification.

2. Certification mark

For different service types of UL, the UL mark can be divided into three categories, the LISTED listing mark, the Classified classification certification mark, and the Recognize component certification mark. UL's services are based not only on American UL standards, but also on Canadian standards (cUL). Therefore, the UL mark is also divided into three types: UL products and cUL products, and both meet these three types. The "us" on the lower right of the UL mark means it is applicable to the United States, the "c" on the lower left means it is applicable to Canada, and both "us" and "c" are applicable in both countries.

3. Certification Standards

4. Test items

1. Input test

2. Temperature rise test

3. Impact/drop test

4. Glow wire/needle flame test

5. Ball pressure test

6. LPS limited power test

7. Touch current test

8. Grounding impedance test

9. Constant temperature and humidity test

10. Vibration test, etc.

5. Required information

1. CDF (Critical Parts List)

2. Schematic

3.PCB Layout

4. Label/nameplate

5. Transformer specifications, inductor specifications

6. Model List/Difference Table

7. Instructions for use or installation of the product, etc.

6. Certification process

1. Quotation;

2. Arrange the payment of related funds

3. Provide application forms, materials, and test samples

4. Test and confirm the report

5. Pass the audit and obtain NOA/NOC

6. NOA can use the UL mark to ship directly, and NOC needs to complete the first factory inspection before using the UL mark to ship

7. Certification cycle and validity period

The UL certification period is usually 3-4 weeks, and it can be expedited, and an additional fee will be charged for expediting.

8. Factory inspection

UL audits the factory four times a year. In addition to the quarterly audit, there is also an annual audit, and the factory is also audited every year.

Materials to be prepared for UL factory audit:

1. Production and quality control procedures

2. Inspection standards for main components and finished products

3. Records of main component certificates (yellow cards)

4. Product material list

5. Main documents for plastic material control

6. Main documents of production control

7. Record of UL label

8. Recycling of Bulk Label for main parts packaging