The diode circuit graphic symbol is printed on the housing, with one side of the vertical line being the negative pole of the diode and the other end being the positive pole of the diode. 2. The diode marked with a colored ring on the casing, with one end of the ring being the negative electrode and the other end being the positive electrode of the diode. There is a difference in the length of the 3 LED pins, with the longer end being the positive pole. 4 high-power diodes, with one threaded end as the negative electrode and the other end as the positive electrode. The rectifier diode usually has a white ring on the black shell, indicating one end as the negative electrode and the other end as the positive electrode. Most diodes are marked with polarity on the casing, some represented by circuit graphical symbols, and some marked with color rings or pin length features. When identifying the polarity of diode pins installed on a circuit board, the polarity of the pins can be identified based on the labeled information near the diode or around the solder joint on the back. In addition, the corresponding circuit diagram can also be found based on the circuit where the diode is located, and pin polarity can be identified based on the circuit graphic symbols in the diagram
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