Hikotek SL320 series data logging sound level meter, designed with quadruple sound range and A/C/Z weighting. According to the measurement object, the sound level detector can be divided into the characteristic measurement of environmental noise (sound field) and the measurement of sound source characteristics; according to the time characteristics of the sound source or sound field, it can be divided into steady-state noise measurement and non-steady-state noise measurement. Unsteady noise can be divided into periodic variation noise, irregular variation noise and impulse sound; according to the frequency characteristics of the sound source or sound field, it can be divided into broadband noise, narrowband noise and noise containing prominent pure tone components; according to the accuracy of measurement requirements, it can be divided into precision measurement, engineering measurement and noise census. The data logging sound level meter can measure both environmental noise and industrial noise, TA652B can connect with PC with the supplied software and graph in real-time. It has sound and light alarm once measurement value over limit.