Water Quality Measurement using Transmittance and 90° Scattering Techniques through Optical Fiber Sensor

This research is the continuance of the previous developed water quality fiber sensor by Omar et al (2007). The application of spectroscopy analysis is the major tasks established in the measurement of the capacity of total suspended solids (TSS) in water sample in the unit of mg/L. The interaction between the incident light and the turbid water sample will leads the light to be either transmitted through the water sample or absorbed and scattered by water molecules and TSS particles. The resultant light produced after the interaction will be collected by plastic optical fiber located at 180deg (transmittance measurement technique) and 90deg (90deg scattering measurement technique) from the incident light. The measurement is done through BLUE and RED Systems with peak response of emitter and detector at 470 nm and 635 nm respectively. Signal interpretation and data display is established through Basic Stamp 2 microcontroller. Transmittance measurement technique has a capability to sense the amount of solids suspended in water as low as 20 mg/L. 90deg measurement technique has a capability to sense the amount of solids suspended in water as low as 10 mg/L. Both measurement techniques recorded a very good linear correlation coefficient and low standard error.