A Low-Cost Tide Measurement System for Water Quality Assessment

This paper presents a low-cost tide measurement system based on a set of two inclinometers. The inclination sensors deliver a DC output voltage which varies linearly with the angle of its working direction. Thus, with two inclinometers assembled in orthogonal directions, it is possible to provide the tide direction and intensity. The tide measurement system was developed for a stand alone operation and includes an RS-232 interface for communication purposes. However, in the present paper an application for water quality assessment is considered and the presented system also includes additional measuring channels, for temperature, electrical conductivity, turbidity and pH measurements. All the measuring channels are connected to a FieldPoint (FP-AI-100) analog input module that works under FP-2000 control. The FP-2000 controller communicates through RS232 with the tide measurement system whose conditioning circuit includes two voltage-to-frequency converters and a universal frequency-to-digital converter (UFDC). Wi-Fi data communication is also provided including an Ethernet-wireless to the FP-2000 Ethernet port. Realtime data processing is supported by a LabVIEW RT software embedded in the FieldPoint controller