Sound Pressure : 94dB and 114 dB Standards : GB/T15173, IEC942 Accuracy : 0.3 dB Accessories: Standard : Main Unit Accessories : Carrying Case and Operating Manual Frequency : 1000ï±0.01% Hz Allows Calibration with A, B, C or D weighting networks or pplications : Calibration of 1* and ½* micro Temperature Coefficient : 0 to 0.01 dB/0C Altitude Effects : Approximately 0.1dB decrease for each 2000 feet increase in altitude from sea level to 12,000 feet elevation, or comparable atmosric pressure change (approximately every 50mm of Hg decrease). Temperature. Range : -10 to +50 0C (operating) -40 to +650C (storage with batteries removed) Power Supply : 4x1.5V AAA (UM-14) Dimensions : 137 x 51 x 51 mm Weight : 200 g