Note: You need to bring your own batteries.Versatile: This digital sound level meter is ideal for measuring ambient noise in various locations, including factories, workshops, schools, residential areas, and offices. It is ideal for noise engineering, quality control, and health prevention applications to ensure that sound levels in various environments meet standards.High Accuracy: This sound level meter offers a measuring range of 30 to 130 dB, an accuracy of ± 1.5 dB to 94 dB and a frequency of 1 kHz, and a display resolution of 0.1 dB. This high accuracy makes it ideal for professional environments and regulatory compliance. Weighted Measurement: Equipped with a weighted filter, the sound level meter automatically adjusts the display range to prioritize the frequencies most audible to the human ear. This feature is essential for accurately assessing ambient noise. Fast/Slow Response Mode: Simply press the "Mode" button to switch between fast and slow response speeds. Fast mode monitors different noise levels in real time, while slow mode provides average measurements, making it ideal for environments with stable noise. Advanced Features: The sound level meter records maximum and minimum sound levels at a standard sampling rate of 0.5 seconds with a maximum error of ±5% and retains data for more than 3 seconds. The "hold" function freezes the measurement on the screen for further analysis; if the measurement exceeds the measurement range, the over-range indicator sounds an alarm, ensuring that all collected data remains within the operating range. Auto-off: After 3 minutes of inactivity, the device automatically turns off to save battery life.