CISPR 24 (EN 55024) vs CISPR 35 (EN 55035)

CISPR 35 (EN 55035) replaced CISPR 24 (EN 55024) as the immunity standard for multimedia equipment. This article explains the key differences, why the change was made, what it means for your product, and Compatible Electronics' NVLAP-accredited testing for both. Part of the Compatible Electronics Learning Center.

The Transition: CISPR 24 to CISPR 35

CISPR 24 (EN 55024) was for many years the immunity standard for information technology equipment (ITE) — products such as computers, printers, monitors, and networking equipment. When CISPR 32 (EN 55032) was introduced as a consolidated emissions standard covering both ITE and broadcast receivers under the new category of "multimedia equipment," a corresponding new immunity standard was needed. That standard is CISPR 35 (EN 55035).

In practical terms: if your product was previously tested to CISPR 24 for immunity and CISPR 22 for emissions, it now falls under CISPR 35 (immunity) and CISPR 32 (emissions). The transition reflects the convergence of computing, audio/video, and communications into a single product ecosystem.

ⓘ Which standard applies to your product? If your product is multimedia equipment — IT equipment, audio/video equipment, broadcast receivers, or any combination — use CISPR 32 (emissions) and CISPR 35 (immunity). CISPR 22 and CISPR 24 are withdrawn standards and should no longer be used for new product compliance in markets that have adopted the successor standards.

Key Differences: CISPR 24 vs. CISPR 35

Scope Expansion

CISPR 24 covered ITE only. CISPR 35 covers all multimedia equipment, which includes ITE but also audio/video equipment and broadcast receivers — previously covered by separate product family immunity standards. The broader scope means fewer edge cases where engineers had to determine which immunity standard applied.

Updated Test Levels

Some immunity test levels and criteria were updated in CISPR 35 to reflect the changed technological landscape — particularly for radiated RF immunity above 1 GHz (CISPR 35 includes spot frequency testing in the 1–6 GHz range that was not in CISPR 24), reflecting the proliferation of wireless transmitters operating in these bands.

Performance Criteria Alignment

CISPR 35 maintains the performance criterion framework from CISPR 24 (Criteria A, B, C) but applies them with updated definitions suited to modern multimedia equipment functions, including streaming, wireless connectivity, and user interface responsiveness.

Port Coverage

CISPR 35 explicitly addresses the wide variety of ports found on modern multimedia equipment — USB, HDMI, DisplayPort, Ethernet, wireless antennas, and audio ports — providing clearer guidance on which immunity tests apply to each port type.

Compatible Electronics Accreditation for Both Standards

Compatible Electronics maintains NVLAP accreditation for testing to both CISPR 24 / EN 55024 (for products requiring compliance to the legacy standard, including through transition periods) and CISPR 35 / EN 55035 (for current compliance). Our engineers can advise on which standard applies to your specific product and market and help you build a complete, efficient test plan.

Standard	Locations Accredited
EN 55035 (2017) + A11 (2020)	Lake Forest/Silverado, Brea, Newbury Park
CISPR 35 (2016)	Lake Forest/Silverado, Brea, Newbury Park
EN 55024 (2010)	Lake Forest/Silverado, Brea, Newbury Park
CISPR 24 (2010) + A1 (2015)	Lake Forest/Silverado, Brea

CISPR 24 (EN 55024) vs CISPR 35 (EN 55035)

CISPR 24 (EN 55024) vs CISPR 35 (EN 55035)

The Transition: CISPR 24 to CISPR 35

Key Differences: CISPR 24 vs. CISPR 35

Scope Expansion

Updated Test Levels

Performance Criteria Alignment

Port Coverage

Compatible Electronics Accreditation for Both Standards

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