Extech SL400 Personal Noise Dosimeter with USB Interface<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Measures frequency weighted noise exposure and peak (C， Z) sound level</li><li>Datalog's up to 999，999 readings when used as a sound level meter with sampling times between 1 second and 24 hours</li><li>Sound level mode: displays sound level， min/max， time-averaged sound level (Leq)， peak， and sound exposure level (SEL)</li><li>Adjustable Criterion Level， Exchange Rate and Threshold</li><li>One user-defined measurement setup</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41-Vv5H-koL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51o37bEDB0L.jpg" noproxy>