Practical guide to CISPR 32 standard: EMI measurements for broadcast and TV devices

Electromagnetic compatibility (EMC) is a crucial aspect for electronic devices, especially in the broadcast and TV sector. The CISPR 32 has extended and updated the requirements of the previous CISPR 13, now establishing limits for the control of radiated and conducted electromagnetic emissions for a wider range of electronic devices.

What does the CISPR 32 standard cover?

CISPR 32 applies to multimedia devices, including radio and TV receivers, video recorders, and other related devices. To ensure compliance, the standard sets specific limits for emissions, including QPK (Quasi-Peak) values, which define the maximum emission threshold for devices across different frequency bands (Figure 1).

Tests are conducted in controlled environments, such as anechoic or semi-anechoic chambers, to minimize reflections and external interference.

The main measurements involve:

• Radiated emissions: verification of electromagnetic waves emitted by the device within a specified frequency range.
• Conducted emissions: analysis of interference transmitted through power and signal cables.

Instrumentation and measurement methodologies

To obtain reliable results, precision instruments such as EMI receivers, log-periodic antennas, LISN (Line Impedance Stabilization Network) and dedicated analysis software are used.

An often overlooked aspect of EMC testing is the proper positioning of antennas. The use of non-metallic, non-reflective support structures is essential to ensure repeatable measurements. For this purpose, the NMR-SB represents an advanced solution to minimize signal reflections emitted from the power cable under test.

The NMR-SB slide bar is completely non-magnetic, non-reflective, and designed to minimize electromagnetic interference during testing. It allows for precise clamp movement with customizable support. Additionally, it is available in a motorized version for even more precise and repeatable measurement control, with the added benefit of fiber optic connection for motor control, thus eliminating common issues associated with other systems such as RS232 or Bluetooth.

Compliance with the CISPR 32 standard is essential to ensure that broadcast and TV devices meet electromagnetic compatibility requirements.. Investing in solutions like the NMR-SB is crucial to obtaining accurate measurements and meeting CISPR 32 standards. Relying on innovative solutions means enhancing device reliability and ensuring excellent performance in compliance with CISPR 32 regulations.