MT-911A 35dB-135dB Digital LCD Sound Level Meter Voice Tester Noise Decibel Monitor Condition: Item Type: Sound Level Meter Material: ABS Applied Standard IEC61672-1 Class 2 Measuring Level Range 35dB-135dB Dynamic Range 50 Decibels Frequency Range 31.5Hz-8KHz Accuracy ±2.0 Decibels Frequency Weighting A Frequency Weighting Time Weighting Fast: 125ms Slow: 1s Microphone 1/2in Electret Condenser Microphone High/low Reading Indication DB100DB, LCD Displays ''Hi'' DB100DB, LCD Displays ''LO'' Temperature Range -20℃~70℃/ -4℉~158℉ Temperature Accuracy ±1.5℃/2.7℉ Resolution 0.1 Data Update 300 Milliseconds Battery Life More Than 60 Hours Automatic Power Off After 15 minutes of no operation, the meter will automatically turn off Battery 3 x 1.5V AAA Battery (Not Included) Operating Conditions -20℃~60℃/-4℉~140℉, 10%RH~90%RH Storage Conditions -20℃~60℃/-4℉~140℉, 10%RH~75%RH Product Size Approx. 144 x 56 x 30.5 mm / 5.7 x 2.2 x 1.2 in Weight Approx. 116g / 4.1oz