Sound Power Label

To provide citizens with a high level of environmental protection, it is necessary to limit noise emissions to the greatest possible extent. Therefore, before placing a product on the Union market, importers and distributors must ensure that the drone bears the CE marking. When required, the UA class identification label and the indication of the sound power level.

To affix the sound label, it is necessary to comply with a series of requirements imposed in Part 13, 14 and 15 of the DELEGATED REGULATION (EU) 2019/945. These sections establish the airborne noise measurement methods to determine the sound power levels of the different classes of UA 1 and 2. In addition, the basic noise emission standards and the test code to measure the sound pressure level produced by the device are detailed and established.

Part 13- Page 39. Noise test code

Part 14- Page 40. Indication of the guaranteed sound power level
PART 15- Page 40. Maximum sound power level per class of UA (including transition periods)

The indication of the sound power level

The indication of the sound power level provided for in Part 14 of the Annex shall be affixed, when applicable, visibly, legibly and indelibly on the UA, unless that is not possible or not warranted on account of the size of the product, and on the packaging.

To determine the sound power level (LWA) of the UA, it is necessary to set up a test area where the device is placed at a sufficient distance from any reflective object that may cause any failure in the sound level measurement.

These tests will be performed with the device turned on, simulating a stationary flight phase, and if it has accessories, tests will be done with all its possible configurations. The noise tests shall be carried out with the UA’s rotors operating at a speed corresponding to the hovering of the UA under MTOM. It will be necessary to perform several tests to corroborate that an acceptable acoustic level has been achieved.

To calculate the surface time-averaged sound pressure level, the following process must be followed. The A-weighted surface time-averaged sound pressure level shall be determined at least three times for each UA configuration. If at least two determined values do not differ by more than 1 dB, further measurements will not be necessary. Otherwise, the measurements shall be continued until two values differing by no more than 1 dB are obtained. The surface time-averaged sound pressure level for calculating the sound power level of a UA configuration is the arithmetic mean of the two highest values that do not differ by more than 1 dB. The report shall contain the technical data necessary to identify the source under test and the noise test code, and the acoustical data.

The maximum sound power level depending on the class of the UA is shown in the following table.