Compact and lightweight design This digital noise meter has a novel design and a small size. Sound Level Meter 30-130dB Noise Monitor Decibel Pressure Calibrator Detector Recorder for Indoor/Outdoor Use.Occasion: Suitable for noise engineering, quality control, health control and various environmental noise measurements. Such as noise measurement applications in factories, offices, traffic roads, homes, audio and other occasions.Max/Min/Lock Current Value - Press the maximum or minimum value, the value will be locked until the minimum or maximum value appears and replaces the current value.Large LCD display, 10 minutes automatic shutdown or manual shutdown by pressing the power button for two seconds.A and C weighing network options: A (simulating human ears), C (machine noise). AC and DC analog signal output, can be connected to a frequency analyzer or X-Y axis recorder for statistical analysis of data.