SMART SENSOR AS844+ Digital Sound Level Meter Decibel Meter Noise Monitor DB Measuring Instrument Condition: Item Type: Sound Level Meter Material: Plastic Color: As shown in the picture Weight: Approx.745g/26.3oz Model: AS844 + Calibrated Sound Source: 94dB @ 1KHz MeasuringRange: 30-130dBA / 35-130dBC Accuracy: ±1.5dB Resolution: 0.1dB Dynamic Range: 50dB / 100dB Overload Indication: OVER / UNDER Frequency Weighting: Characteristics A and C. Digital Display: 31/2 digits Analog Bar Chart: 1dB / 1 bar chart SamplingRate: 20 times / sec AC Signal Output: 1 Vrms / full strip grph Dynamic Characteristics: FAST / SLOW Data Storage Capacity: 15000 Maximum Hold: Support Automatic Power Off: No operation after 10 minutes Microphone: 1/2 inch polarized capacitor Power: 3.7V lithium battery 1000mAh / USB 5V Battery Life: 12 hours (continue use) Temperature Measurement Range: 0-45 ° C Temperature Accuracy: ± 2 ° C Humidity Measurement Range: 10-99% RH Humidity Accuracy: ±5% RH