DS EN 27574-3:1991 Acoustics - Statistical Methods For Determining And Verifying Stated Noise Emission Values Of Machinery And Equipment - Part 3: Simple (Transition) Method For Stated Values For Batches Of Machines Gives guidelines for determining the labelled value Lc, by the labeller and specifies a simple method for verifying compliance of the noise emissions of a batch (lot) of machinery or equipment with it