à¤Ã×èͧÁ×ÍÇÔ·ÂÒÈÒʵÃì ÍØ»¡Ã³ìÇÔ·ÂÒÈÒʵÃì à¤Ã×èͧÇÑ´ÃдѺ¤ÇÒÁ´Ñ§àÊÕ§ Sound Meter > à¤Ã×èͧÇÑ´àÊÕ§ Sound Level Alert with Alarm Extech SL130G Built-in LEDs alert user when sound level is too high or too low " Meets ANSI Type 2 and EN 60651 accuracy specs - compliant to OSHA " Sound Level Alert with Alarm Built-in LEDs alert user when sound level is too high or too low Bright LEDs (red flashing or green) alert user when sound level is too high or too low - LEDs can be read from 30m (100ft) Continuous Monitoring of Sound Level Wall, desk or tripod mount with optional 15ft (5m) microphone extension cable for remote monitoring User settable high or low limit (30 to 130dB) with output to drive external relay module Meets ANSI Type 2 and EN 60651 accuracy specs - compliant