â·ÃÊͺ¶ÒÁÃÒ¤Ò The Extech SL130G continuously monitors the sound level and has built-in LEDs that alert the user when the sound level is too high or too low. SL130G: Sound Level Alert with Alarm 30-130dB Meter with built-in under/over-range LEDs indicators Features: Wall, desk or tripod mount with optional 15ft (5m) microphone extension cable for remote monitoring Bright LEDs (red flashing or green) can be read from 100ft (30m) Continuous monitoring of sound level in 3 ranges: 30 to 80dB, 60 to 110dB, 80 to 130dB User adjustable high or low limit (30 to 130dB) with output to drive external relay module Built-in desk, wall and tripod mounts Meets ANSI Type 2 and EN 60651 accuracy specs - compliant to OSHA Complete with 100-240V AC 50/60Hz adaptor and microphone wind cover Specifications: Display: 4.6"x3.125" multi-function LCD Frequency Bandwidth: 31.5Hz to 8kHz Microphone: 0.5" electret condenser microphone (remoteable) Measurement Ranges: 30 to 80dB, 60 to 110dB, 80 to 130dB Frequency Weighting: A & C (programmable) Response Time: Fast (125ms), Slow (1s) (programmable) Resolution: 0.1dB Alarm Output: 3.5mm mono phone plug, maximum: 3.4mA @ 5 VDC Minimum Output Voltage: 2.5 VDC Power: AC/DC adapter for full functions; 8xAA batteries for monitoring function only without LED alert Dimensions: 8.75"x7.1"x1.25" (22x18x3.2mm) Weight: 0.63 lbs. (285g) CE: Yes Warranty: 1 year Alarm Extech SL130G Sound Level Meter Sound Meter à¤Ã×èͧÇÑ´¤ÇÒÁ´Ñ§àÊÕ§ à¤Ã×èͧÇÑ´àÊÕ§