Features:
Data storage 
Built in calibration mode 
A,C & F frequency weightings 
Measuring level and time level selection

Applications:
Sound level meters are commonly used in noise pollution studies for the quantification of different kinds of noise, especially for industrial, environmental, mining  and aircraft noise.

Measuring Principle:
Sound level meter measures the sound level in logarithmic scale. There is a diaphragm in the microphone which responds to changes in air pressure caused by sound waves. This sound pressure is converted into logarithmic scale and displayed.