SMART SENSOR AR824 Digital Sound Level Meter Noise Tester Measuring Tool Features: 1.  2. This sound level has instantaneous sound measure function 3. The measurement range is 30-130dB 4. With two equivalent weighted sound pressure levels, A and C 5. Suitable for measuring noise of industrial, environmental and aircraft.   Specification: Condition: Brand: SMART SENSOR Model: AR824  Material:  ABS Plastic  Digit & Resolution      5 digits & 0.1dB Display: 0.5 secretary  Measuring Range:  30~130dBA 35~135dBC  Accuracy  ±1.5dB  Frequency range:  31.5Hz to 8.5K Hz  Linearity range:  50dB  Frequency weighting:   A, C  Microphone  1/2 inch Electret Condenser microphone  Standard      According to IEC651 TYPE 2 & ANSIS1.4 TYPE 2  Time Weighting  Fast / Slow  Bar graph:      50 dB scale at 1 dB step fro monitoring  current sound pressure level display period: 50mS  Level ranges:        30-80dB; 50-100dB; 60-110 dB; 80-130dB  Over indicate over range:       Under indicate less than lower limit for the range                                         AC output:        0.707 Vrms at FS output impedance approx 600Ω  DC output:       10mV / dB output impedance approx 100Ω  Max: Maximum hold / Auto Power Off      Yes  External power supply   Yes  Level Range Bar Graph  Yes  Range Selection        4 modes  Range Over Indication / Battery Indication  Yes  Backlight Display /  Max & Min Hold Function   Yes  Sampling Frequency        2 times / sec  Self calibration time:       10 secs(every turn on)  Operating condition       Temperature :0-40℃ ; Humidity: 10% to 80%RH  Storage Condition                                                      Temperature: -10 to 60℃ ; Humidity: 10% to 70% RH  Power   4 * AA1.5 alkaline cells ( battery not include) Weight: Approx. 617g / 21.8oz Size:Approx. 224 * 66 * 33mm / 8.8 * 2.6 * 1.3in   Package List: 1 x Sound Level Meter 1 x DC Cable 1 x User Manual