What is CISPR 36?

CISPR 36 is an EMC emission standard that specifies emission limits and methods of measurement for radiated emission (i.e., magnetic field emission) emitted from electric and hybrid electric road vehicles in the frequency range of 150 KHz to 30 MHz. The document of this standard describes radiated emission limits for a 3 m measurement distance. The emission test of this document measures the magnetic field emissions being produced by the vehicle (on all 4 sides) at a test distance of 3 meters. The purpose of the CISPR 36 standard is to provide protection for offboard receivers used in the residential environment (at 10 m distance) from the electric vehicle magnetic field emission in the frequency range of 150 kHz to 30 MHz. 

In simple words, this standard provides protection for offboard receivers (such as AM receivers) used in the residential environment from the radiated emission (i.e., magnetic field emission) emitted from the electric and hybrid electric road vehicles at a distance of 10 m (frequency range of 150 KHz to 30 MHz). These offboard receivers could be near the vehicles passing by. As per this document, examples of a residential environment include rooming houses, private dwellings, entertainment halls, theatres, schools, public streets, shopping canters/malls, etc.

CISPR 36 standard applies to electromagnetic energy emissions that are emitted from electric and hybrid electric vehicles propelled by an internal traction battery when operated on the road. The standard is applicable to vehicles that feature battery voltage between 100 V and 1000 V. This document only apply to road vehicles where an electric propulsion is used for a sustained speed of more than 6 km/h. The CISPR 36 standard ensures that these vehicles that comply with this standard do not emit more than the radiated emission limit specified in this standard and do not interfere with other offboard receivers located at a distance of 10 m in the same environment. 

The scope of CISPR 36 not included the electric vehicles to which CISPR 14-1 applies. The scope of this international standard does not include Vehicles where the electric motor is only used to start up the internal combustion engine (e.g., "micro-hybrid") and also does not include vehicles where the electric motor is used for additional propulsion only during acceleration (e.g., "48 V mild hybrid vehicles").  The radiated emission requirements described in this document does not apply to the intentional transmissions from a radio transmitter as defined by the ITU (International Telecommunication Union), including their spurious emissions. 

Required test site and measuring instruments for CISPR 36: 

The test site of this standard shall be OTS (outdoor test site), OATS (Open Area Test Site), or ALSE (Absorber Lined Shielded Enclosure). The measurement instruments used in this test include a measuring receiver, spectrum analyzer, preamplifier, magnetic field antennas, and other supporting equipment.

Figure 1: Measuring site (OTS) for vehicles

 CISPR 36 specifies the following limits for radiated disturbances (magnetic field emission):

Table 1 provides the emission limit for magnetic field emissions measured (in dB(µA/m) with the quasi-peak detector at 3 m antenna distance. Figure 2 shows Table 1 graphically. For accurate determination, the formula provided in this table shall be used.

Table 1: 

Figure 2: Limits of magnetic field disturbance (quasi-peak detector) at 3 m antenna distance, (as per table formula)

 Comparison between other automotive emission standards:  

Three automotive emission standards are available: CISPR 36, CISPR 25, and CISPR 12. Let's see the difference between these standards.  

Note 1: The CISPR 25 standards objective is to provide protection for on-board receivers installed in a vehicle from the radio frequency disturbances produced by components/modules in the same vehicle.

Note 2: The objective CISPR 36 is to provide protection for off-board receivers (at 10 m distance) in the frequency range of 150 kHz to 30 MHz.

Note 3: The objective of CISPR 12 is to provide protection for off-board receivers (at 10 m distance) in the frequency range of 30 MHz to 1000 MHz. In terms of emission measurement, the CISPR 12 is a complimentary standard of CISPR 36, the only difference is the test setups and measurement frequencies. The CISPR 36 standard was developed to cover emission measurements for vehicles in lower frequency bands that are not covered in the CISPR 12.

CISPR 36:2020: CISPR 36:2020 is the latest version of the standard.