CISPR 12: Vehicles, boats, and internal combustion engine driven devices

CISPR 12 is equivalent to the SAE J 551-2 standard for the following: vehicles, boats, and internal combustion engine-driven devices - radio disturbance characteristics - limits and methods of measurement.

Test setup according to CISPR12 typically is as follows:

• a monopole is used for the range 150 KHz to 30 MHz only vertical polarization measurements are made
• for 30 MHz to 200 MHz, a biconical antenna is used
• the log-periodic is used for the range 200 MHz-1000 MHz
• a biconical antenna is used, the log-periodic is used for the range 200 MHz-10000 MHz
• tuned dipoles can be used for the entire range.
• For 10 m testing, the antenna is 10 meters from the outer skin of the vehicle and in line with engine midpoint.
• Both sides of the vehicle are tested. For 3 m testing antenna is placed at 1.8 m both polarizations are measured.

According to CISPR 12, the chamber must be correlated to OATS. An NSA measurement showing a small deviation should demonstrate that development.

This standard applies to the emission of electromagnetic energy which may cause interference to radio reception and which is emitted from

a) vehicles propelled by an internal combustion engine, electrical means or both (see 3.1);

b) boats propelled by an internal combustion engine, electrical means or both (see 3.2). Boats are to be tested in the same manner as vehicles except where they have unique characteristics as explicitly stated in this standard

c) devices equipped with internal combustion engines (see 3.3). See Annex G for a flow chart to help determine the applicability of CISPR 12.

This standard does not apply to aircraft, traction systems (railway, tramway, and electric trolley bus), or incomplete vehicles. In the case of a dual-mode trolley bus (e.g. propelled by power from either a.c./d.c. mains or an internal combustion engine), the internal combustion propulsion system must be included, but the AC/DC mains portion of the vehicle propulsion system is excluded from this standard.

The measurement of electromagnetic disturbances, while the vehicle is connected to power mains for charging is not covered in this standard. The user is referred to appropriate IEC and CISPR standards which define measurement techniques and limits for this condition.