Key takeaways
CISPR 25 is the international standard and GB 18655 is the nationally adopted standard, and their technical content is highly consistent. Domestic testing and regulatory compliance usually cite GB 18655, while exports to the EU cite CISPR 25. In practice the two reports can substitute for one another; the differences are mainly in band subdivision detail and limit severity.
CISPR 25 and GB 18655 are technically near-equivalent. GB 18655 is the national standard that adopts CISPR 25 of the International Electrotechnical Commission identically. Understand that and you understand the difference in where each applies.
1. The relationship between the two
CISPR 25 is titled "Vehicles, boats and internal combustion engines — Radio disturbance characteristics — Limits and methods of measurement for the protection of on-board receivers", and is issued by the International Special Committee on Radio Interference. The limits in GB 18655, "Vehicles, boats and internal combustion engines — Radio disturbance characteristics", derive from CISPR 25.
Domestic regulation (such as GB 30512 and compulsory certification) mostly cites GB 18655; for products exported to the EU, certification bodies generally cite CISPR 25.
2. Where they actually differ
- Frequency band division: the overall framework matches, with minor differences in some band boundaries and measurement bandwidths
- Strictness of limits: GB 18655 is slightly stricter than CISPR 25 in a few bands
- Scope: CISPR 25 addresses on-board electronics (12 V / 24 V systems); GB 18655 covers vehicles, boats and internal combustion engines
- Where it is cited: domestic regulatory compliance uses the national standard, export certification uses the international one
3. Which one to cite in an actual test
For domestic OEM submissions and compulsory certification: cite GB 18655. For EU export or where the customer specifies: cite CISPR 25. Projects sometimes require both, in which case separate reports are issued to each standard with the conclusions marked separately.
The key is to confirm the cited edition with the requester — standards are revised periodically, and a different edition year brings adjusted limits and test methods.
4. Watch the edition
Taking CISPR 25 as the example, different edition years carry revisions to the high-frequency limits and measurement methods. Always confirm the currently valid edition number before submitting samples, so a wrong edition does not get the report returned.
Turnaround time is arranged according to the actual project. You are welcome to state your target date when submitting samples; we will check it against the current schedule, confirm a feasible plan with you, and update you at each milestone.
