SOUND LEVEL METER This Unit Was Designed According To Following Standards: A. International Electrician Committee Standard: Iec Pub 651 Type2 B. Us National Standard: Ansi S1.4 Type2 Measuring Range: 30~130 Dba Accuracy: ±1.5 Db Digit & Resolution: 4 Digits & 0.1 Db Frequency Response: 31.5hz ~8.5khz Frequency Weighting Characteristic: A Sampling Rate: 2times/Second Microphone：1/2 Inch Polarization Capacitance Microphone Max Reading Automatic Backlight Low Battery Indication Automatic Power Off Packing Method: Blister + Card Power: 9v Battery (6f22) Dimension: 57*36*149mm Weight: 144g (Including Battery)