DESIGN AND DEVELOPMENT OF THE SINGLE PHASE VIRTUAL LOCK-IN AMPLIFIER WITH EXTERNAL REFERENCE BASED ON LABVIEW AND VERNIER SENSOR DAQ

• Main Author: RATRI PRASTIKA (NIM: 20214044), LINTANG
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22911
• Institution: Institut Teknologi Bandung

In this research has been carried out the design and development of instruments lock-in amplifier based software (virtual-LIA). Virtual-LIA designed using Vernier sensorDAQ as data acquisition and LabVIEW 2011 software as the media making the program. The design of virtual-LIA based on the working principle of mathematical operations of LIA. The type of the virtual-LIA is a single phase with the external reference signal processing capabilities. The test is done in three ways that are: testing the program of virtual-LIA by processing a periodic signal from the signal generator in LabVIEW, test the accuracy of the reading analog input terminal Vernier SensorDAQ by processing a periodic signal of a hardware signal generator, and use the virtual-LIA for the real measurement on the experiment voltage divider circuit and the light transmission experiment. The percentage of the measurement accuracy in simulation test show the value of 98% of the simulation without noise and 96.3% for the simulation with noise. The percentage of the measurement accuracy of the test results using a signal generator indicates the value of 96%. The percentage of the measurement accuracy of the test results in the real experiments that show the value of 94% for the experiment simple voltage divider circuit, 99,14% for experiment of mica’s transmission, and 96,4% for transmission of formazin polymer suspension experiment. Overall the percentage of virtual-LIA accuracy of the measurements that have been developed in this research has reached 96,64%.