... statistics, noise acquisition, noise frequency analysis2. built-in 1/1 frequency spectrum filter, RS-232C connector3. equipped with printer to realize spot printing4 ... ,L90,Lmax,SD,Ld,Ln,Ldn,1/1 frequency spectrumFilter characteristics1/1 frequency intervalcentre frequency: 31.5Hz,63Hz,125Hz,500Hz,1kHz,2kHz,4kHz ... : 178mm×81mm×31mmWeight 0.4kg , printer: 0.41kg digital sound frequency analysis meter