1、Multi Function Environmental Tester: Measure environmental temperature, humidity, altitude, pressure, illumination, and A C weighted decibels. Features data hold, unit switch, backlit color screen, and maximum display. 2、Versatile Usage: Ideal for accurate and non destructive environmental measurements in laboratories, workshops, outdoors, libraries, indoor lighting inspection, moisture detection, altitude testing, noise level analysis in homes, cars, and hospitals. 3、Noise Decibel A C Weighting: Switch between dBA dBC modes for noise measurement, with maximum reading lock function. Measure noise levels from 30 to 130 decibels with accuracy. Position noise receiver properly for optimal results. 4、Accurate Illumination Detection: Measure brightness and light accurately with LX FC switch. Converts light strength to digital display or analog signal output. Utilizes silicon photodiodes or selenium cells for photoelectric effects. 5、Altitude and Pressure Test: Test altitude, pressure, temperature, and humidity accurately. Allow the device to sit stationary for 5 to 10 minutes for more accurate readings. Built in barometer adjusts atmospheric pressure based on weather conditions.