RANCANG BANGUN OTOMATISASI SISTEM PENGUKURAN SERAPAN AKUSTIK BAHAN MENGGUNAKAN TABUNG IMPEDANSI DUA MIKROFON

A low cost microcontroller based automatic data acquisition system has been developed to measure the acoustic absorption coefficient of materials using dual microphone impedance tube. The output is presented in the dimensions of voltage (volt) and intensity level (dB). The goal of this research is to design and to develop a prototype of an acoustic absorption of materials measuring tool. The intensity level of SAD is calibrated using type Extech 407730 standard sound level meter. The validation result shows that the accuracy level of sensor 1 of VSLM-LJMA8535 is 96.3%, sensor 2 is 95.7%, sensor 3 is 96.3%, the range of measurement is 75-110dB with an accuracy tolerance of ±0.05dB, and the sensitivity of sensor 1 is 4.47 dB/V, sensor 2 5.73 dB/V, and sensor 3 4.47 dB/V. In this research VSLM-LJMA8535 is used to measure the acoustic absorption coefficient of a few types of wood