APLIKASI SENSOR FOTODIODA PADA VISKOMETER METODE BOLA JATUH BERBANTUKAN KOMPUTER

Abstract

The measurement of viscosity with falling ball methods has three disadvantages i.e 1) mistaken in observing of the moving ball due to parallax error, 2) fatigue on observer’s eye and 3) inaccuracy in recording the interval time of falling ball since asynchronous of moving ball observed and time record. This research aims to complete and develop the measurement of fluid viscosity using falling ball methods. The development of the instrument by the use of photodiode sensor coupling with pointer laser as time detector that capable to measure time interval up to millisecond. The development of instrument using personal computer to measure and calculate the viscosity value so the data can be obtained directly and displayed on the computer monitor in real time. The testing of the instruments has been applied to three different palm and machine oils with different in density. This results showed that the design of the viscometer worked properly in measuring the sample viscosity of palm and machine oils with more consistence and small deviation than the manual measurement. This viscometer is able to be used to measure the fluid viscosity with opaque degree equal to a mixture of 20 ml of water and 0,08 ml of ink (about 4 drop inks), in which the photodiode current produced  was 9.25 mA.

Keywords: photodiode, viscosity, falling ball method and computer