... TL5670B integral impulse sound level meter is precise acoustics measuring equipment. It meets JJG188-2002 sound level meter verification standard ... slow(S), Max holdDetector True effective value, crest factor≥10Automatic measuring and storageLeq, Lae, SD, Lmin, L95, L90, L50, ... acquisition and storage: 200 teams of data single team Measuring time setting and clockMan, 10s,1min,5min,10min,20min, ...