DIN EN 62479 / VDE 0848-479

DIN EN IEC 62479 is a standard for assessing the conformity of low-power devices with limits for exposure to electromagnetic fields (EMF).

Purpose: Simplified conformity assessment of low-power electrical/electronic equipment (10 MHz to 300 GHz) with regard to EMF limits.

Scope of application: Devices with low transmitting power (e.g. IoT sensors, wearables, miniature transmitters) for which no product-specific standards exist.

Tests:

• Determination of the “Low-Power Exclusion Level”: A limit value for the maximum radiated power, below which no further EMF assessment is required.

• Calculation or measurement of the Available Antenna Power or Average Total Radiated Power.

• If the exclusion level is exceeded: Application of other standards (e.g. DIN EN IEC 62311).

• Documentation: Specification of the methods used, uncertainty analysis and declaration of conformity.

• Special features: Consideration of pulsed fields and near-body applications (see Annex B).

Content, scope and tests:

Content of the standard:

DIN EN IEC 62479 provides a simplified procedure for the conformity assessment of devices with low power output. It defines a “Low-Power Exclusion Level”, which is derived on the basis of the specific absorption rate (SAR) or power density. Devices whose radiated power is below this limit are automatically considered compliant and require no further EMF assessment.

The standard includes:

• Calculation methods: mathematical models to determine the maximum radiated power under reference conditions.

• Measurement methods: Practical measurements of E-field and H-field strengths at defined distances.

• Adaptations for special cases: Pulsed fields: Time-averaged assessment of exposure. Applications close to the body: Adjustment of the exclusion level for devices operated less than 20 cm from the body (e.g. smartwatches).

Scope of application:

The standard applies to:

• Frequency range: 10 MHz to 300 GHz (e.g. Bluetooth, WLAN, 5G millimeter waves).

• Device categories: Low-power devices with a transmitting power below 50 mW (e.g. RFID tags, medical sensors). Unintentional emitters such as switching power supplies or microcontrollers.

• Exceptions: High-power devices (e.g. mobile phone base stations) are subject to product-specific standards such as IEC 62232.

Tests to be performed:

Test conditions:

• Operating conditions: Tests under maximum transmission power and realistic usage scenarios.

• Environment: Standardized laboratory conditions (temperature: 23 ±5 °C, humidity: 30-60 %).

Sample preparation:

• Device configuration: Test in standard version, if necessary with antennas or accessories.

• Measuring distance: Typically 20 cm for applications away from the body and 5 cm for applications close to the body1.

Evaluation:

• Comparison with limit values: If the calculated PmaxPmax is not reached, the device is compliant.

Documentation:

• Test report: Contains measurement methods, device specifications, uncertainty analysis (±30 % as standard) and declaration of conformity.

• Proof of repeatability: Specification of the measuring device calibration and test environment conditions.

Alternative standards:

1. IEC 62311: Generic EMF assessment for devices outside the low power range.

2. EN 50371: Predecessor standard to DIN EN IEC 62479 (replaced by EN 62479:2010).

3. IEC 62232: Assessment of exposure from radio base stations.

4. ICNIRP guidelines: Internationally recognized limits for EMF exposure.

5. IEC 62477-1: Safety requirements for power electronic systems.