IEC 61326 EMC Testing for Measurement, Control & Laboratory Equipment

IEC 61326 EMC Testing Services

Compatible Electronics provides comprehensive IEC 61326 EMC testing for measurement, control, and laboratory equipment. Our NVLAP accredited laboratory holds direct accreditation for IEC 61326-1 and the IEC 61326-2 particular requirements series — covering both emissions and immunity at three California locations.

NVLAP Accredited ILAC MRA Recognized ISO/IEC 17025:2017 Emissions + Immunity

What is IEC 61326?

IEC 61326 specifies EMC requirements for electrical equipment used in measurement, control, and laboratory applications. Unlike generic EMC standards, IEC 61326 addresses the unique challenge these instruments face: they must operate accurately in electromagnetic environments while not generating interference that disrupts nearby equipment.

The standard applies to professional, industrial process, and educational use equipment powered from AC mains, DC supply, or batteries when connected to mains for charging. It covers both emissions (how much interference the equipment generates) and immunity (how well the equipment withstands interference from its environment), with performance criteria tied directly to the equipment's measurement function.

IEC 61326 is the required EMC standard for CE marking under the EMC Directive 2014/30/EU for instrumentation and measurement equipment. EN 61326-1 (the European adoption) is a harmonized standard under this directive, providing presumption of conformity when testing is completed to its requirements.

IEC 61326 Standard Series — Accredited Scope

Compatible Electronics holds NVLAP accreditation for the following IEC 61326 standards, confirmed in our accredited scope effective 2025-06-05 through 2026-06-30:

General Requirements

IEC 61326-1 (2005-12) & EN 61326-1

IEC 61326-1 (2005-12) — accredited at Lake Forest/Silverado, Brea, and Newbury Park
EN 61326-1 (2006) — accredited at Lake Forest/Silverado and Brea
EN 61326-1 (2013) — accredited at all three California locations
General EMC requirements for all measurement, control, and lab equipment

Sensitive Instruments

IEC 61326-2-1

IEC 61326-2-1 (2005) — accredited at all three California locations
Particular requirements for sensitive test and measurement equipment
EMC unprotected applications with enhanced immunity requirements
Modified performance criteria for high-sensitivity instruments

Portable Test Equipment

IEC 61326-2-2

IEC 61326-2-2 (2005) — accredited at all three California locations
Portable test, measuring, and monitoring equipment
Equipment used in low-voltage distribution systems
Handheld and portable instrument requirements

Transducers

IEC 61326-2-3 & EN 61326-2-3

IEC 61326-2-3 (2006) — accredited at all three locations
EN 61326-2-3 (2013) — accredited at all three locations
Transducers with integrated or remote signal conditioning
Field-mounted process instrumentation

IVD Medical Equipment

IEC 61326-2-6

IEC 61326-2-6 Ed. 1.0 (2005-12) — accredited at all three California locations
In vitro diagnostic (IVD) medical equipment EMC
Clinical laboratory environment requirements
Coordination with IEC 61010-2-101 safety requirements

Equipment We Test

Test & Measurement

Electronic Test Instruments

Oscilloscopes and signal analyzers
Multimeters and clamp meters
Signal generators and function generators
Power analyzers and energy meters
LCR meters and impedance analyzers

Industrial Control

Process Control Equipment

Programmable logic controllers (PLCs)
Process controllers and regulators
Industrial sensors and transducers
Data acquisition systems (DAQ)
HMI panels and operator interfaces

Laboratory

Laboratory Analytical Equipment

Analytical balances and scales
Spectrophotometers and spectrometers
Environmental monitoring instruments
Chromatography equipment
In vitro diagnostic instruments

EMC Emissions Testing — IEC 61326

Radiated Emissions

CISPR 11 Radiated

Group 1 equipment classification (non-ISM use of RF energy)
Class A limits for industrial environments
Class B limits for residential/commercial environments
Measurements at 10 m or 3 m normalized distance

Conducted Emissions

CISPR 11 Conducted (150 kHz – 30 MHz)

AC mains conducted emissions via LISN
Class A and Class B limit assessment
Quasi-peak and average detector measurements
All live conductors tested

Power Quality

Harmonic Current & Flicker

IEC 61000-3-2 harmonic current emissions (≤16 A per phase)
IEC 61000-3-3 voltage fluctuations and flicker
Applicable to equipment connected to public low-voltage supply

EMC Immunity Testing — IEC 61326

IEC 61000-4-2

ESD Immunity

Contact and air discharge test levels
Enclosure port testing
Performance criterion assessment per equipment function

IEC 61000-4-3

Radiated RF Immunity

80 MHz to 1 GHz (and above where required)
3 V/m or 10 V/m depending on environment
AM modulated test signal; 80% AM at 1 kHz

IEC 61000-4-4

EFT/Burst Immunity

AC mains and signal/control port testing
1 kV on power ports; 0.5 kV on signal ports (basic environment)
Higher levels for industrial environments

IEC 61000-4-5

Surge Immunity

Line-to-line and line-to-earth surge testing
0.5 kV and 1 kV levels on power ports
Signal port surge where applicable

IEC 61000-4-6

Conducted RF Immunity

150 kHz to 80 MHz frequency range
3 Vrms or 10 Vrms depending on environment
Power, signal, and control port injection

IEC 61000-4-8

Power Frequency Magnetic Field

30 A/m (basic) or 100 A/m (industrial) continuous
Enclosure port magnetic field exposure

IEC 61000-4-11

Voltage Dips & Interruptions

Voltage dips: 0%, 40%, 70% reductions
Short interruptions and voltage variations
Performance criterion A, B, or C per equipment function

Performance Criteria

IEC 61326 requires that the equipment's ability to perform its intended measurement function be assessed during and after each immunity test. The standard defines three performance criteria:

Criterion A — Normal Performance

The equipment continues to operate as intended during and after the immunity test. No degradation of performance or loss of function beyond limits specified by the manufacturer.

Criterion B — Temporary Degradation

The equipment may experience temporary degradation of performance during the test, but recovers automatically without operator intervention after the test stimulus is removed.

Criterion C — Operator Intervention Required

The equipment may experience temporary loss of function that requires operator intervention (such as a restart) to restore normal operation. Loss of stored data is not permitted unless explicitly allowed.

The acceptable performance criterion for each test is defined by the equipment manufacturer based on the equipment's intended function. IEC 61326-1 specifies default criteria for each immunity test; IEC 61326-2 particular requirements may modify these for specific equipment types.

Real-World Testing Examples

Portable Power Quality Analyzer — IEC 61326-2-2 + CE Marking

A manufacturer of a handheld power quality analyzer used in LV distribution systems needed CE marking under the EMC Directive. The instrument is classified under IEC 61326-2-2 (portable test and measuring equipment used in low-voltage distribution systems). Compatible Electronics performed CISPR 11 conducted and radiated emissions (Class B), and the full IEC 61000-4 series immunity test plan with Criterion A performance assessment during signal port and power port tests. The NVLAP accredited EN 61326-1 (2013) test report supported the EU Declaration of Conformity. The same emissions data also supported ICES-003 compliance for the Canadian market.

Industrial PLC System — IEC 61326-1 Industrial Environment + EN 61000-6-2

A process automation manufacturer needed EMC compliance for a modular PLC system deployed in heavy industrial environments. The system was tested to IEC 61326-1 (2013) at the industrial electromagnetic environment test levels — 10 V/m radiated RF immunity, 10 Vrms conducted RF immunity, 2 kV surge on power ports, and 100 A/m magnetic field. Compatible Electronics documented performance criterion A throughout all immunity tests, with the PLC continuing to execute its control program without deviation. The test package supported CE marking under both the EMC Directive and Machinery Directive for the EU industrial market.

In Vitro Diagnostic Analyzer — IEC 61326-2-6 + IEC 60601-1-2

A clinical laboratory equipment manufacturer needed dual compliance for an automated biochemistry analyzer: IEC 61326-2-6 for EMC (the IVD-specific part of 61326) and IEC 60601-1-2 Ed. 4 for medical electrical equipment EMC. Compatible Electronics coordinated a combined test plan covering CISPR 11 emissions, the IEC 61000-4 series immunity tests at IVD-appropriate levels, and the additional immunity tests required by IEC 60601-1-2 Ed. 4 for professional healthcare facilities. Performance criterion was assessed against the analyzer's reportable measurement range throughout all immunity tests. The ILAC MRA accredited test reports supported simultaneous CE marking and FDA 510(k) submissions.