The device is designed to meet the measurement requirements of safety engineers, health, industrial safety offices and sound quality control in a variety of environments including factories, offices, traffic, homes and audio systems. This is an easy to use and convenient mini sound level meter. Designed for sound quality control, it measures sound levels from 30dBA to 130dBA. It has auto range, wide measurement and frequency range (31.5Hz ~ 8.5KHz), maximum hold, frequency weighting A and automatic backlight. With the push of a button, the reading is displayed instantly. A useful little tool ideal for noise pollution monitoring, home theater setups, health and safety compliance, vehicle noise testing and more. The automatic backlight has a light sensor on top of the LCD that detects ambient lighting conditions. As ambient lighting conditions dim, the lighting display is enhanced. The darker the environment, the brighter the lighting. Additionally, it reads in dBA and provides a windshield to filter out unwanted signals. Specification: Measuring range: 30~130dBA Accuracy: ±1.5dB Resolution: 0.1dB Frequency range: 31.5HZ～8.5KHZ Frequency weighting: A Sampling frequency: 2 times/second Digital display: 4 digits Microphone: 1/2" electret condenser microphone Automatic shut-down low battery indicator Maximum hold function operating conditions Temperature: 0~40°C (32~104°F) Humidity: 10~80%RH Storage Temperature: -10~60°C (14~140°F) Humidity: 10~70%RH