This sound level meter data-logger is durable and usable for a very broad field of application such as machines, traffic, vehicle, architecture acoustics, environment noise and electric noise, ship, office environment, workshop, flight and other noise. Fit for industry environment protecting, working, sanitation, teaching research and other departments.Specifications:Standardization: IEC651 Type 2 , ANSI S1. 4 Type 2PC interface: USB Drive Software + RS232C Jack-to-Serial Cable with FREE Serial to USB Adapter Support WIN 8Measurement range: Lp : 30~130dB (A) ,35~130dB (C) , 35~130dB (F)Leq : 30~130dB (10s,1m,5m,10m,5m,30m,1h,8h,24h interval)LN. : 0~100%Resolution: 0.1dBAccuracy: ±1dBFrequency range: 20.0 ~ 12,500HzFrequency weighting: A,C & F (Flat)Built-in calibration signals : 94dB at 1kHz (sinusoidal) Memory: 30 groups maxTime weighting: FAST125mS,SLOW: 1 sec.DC output: 0~1.3V,10mv/dBMicrophone: 0.5" Electret condenser microphoneDisplay: 14mm (0.55") LCD Screen with backlightBuilt-in battery condition indicatorAlarm: electron, adjustable,30~130dB set, LED and optional relay contact (NC) outputPower off: Manual or adjustable Auto Power off timePower supply: 4 x 1.5v AAA (UM-4 battery) or External 6V DC 100mA (not included)Size: 236 x 63 x 26 mmWeight: 170g (excluding batteries) Set Includes:1 x Sound Level Meter1 x USB Drive Software1 x Windscreen Filter Ball1 x English instruction bookletHard plastic carry case