1.digital detection,auto test range conversion,wide dynamic range, 2.GB/T 3785,1-2010,GB/T 15952,IEC61672 3.30- ... meter standard and individual sound exposure meter standard of GB/T 15952.digital detection, automatic measuring range conversion, wide dynamic range, ... GB/T 3785,1-2010, IEC61672,GB/T 15952LCD digital displayfrequency range: 20Hz-12.5kHz Modal ...