CISPR 24: Immunity Testing of ITE

CISPR 24 is a test standard for the immunity testing of information technology equipment (ITE). The standard covers ITE which operate within the frequency range of 0 Hz to 400 GHz. CISPR 24 focuses on the simulation of continuous, transient conducted and radiated disturbances, including the following tests: surge, magnetic field, power interruptions, electrostatic discharge (ESD), radio frequency interference (RFI) and electrical fast transients (EFT). This standard stipulates the minimum level of intrinsic immunity ITE must possess to pass EMC testing and operate as designed to in the real world. The requirements apply to ITE on a port by port approach; CISPR defines ports as falling under the category of earth, signal, AC power, DC power or telecommunication ports.

CISPR 24 is identical to EN 55024, its European Union counterpart. To achieve compliance with the European EMC Directive 2004/108/EC, however, ITE also need to be tested for spurious signal levels according to EN 55022 practices. Equipment power through AC mains may require power line harmonics and power line flicker testing as well.
The term ITE is defined by CISPR 24/EN55024 as encompassing the following devices:

• Central processing units and peripherals (i.e. processor storage)
• Minicomputers
• Midrange computers
• Microcomputers
• Personal computers and peripheral units
• Special purpose systems (i.e. word processing)
• Communication devices used for transmission of data (i.e. modems)
• Input-output units (i.e. card readers)