Distributed virtual instrument for water quality monitoring across the Internet

This paper shows the design of a distributed and multi-platform system for water quality monitoring, enhanced with Internet capabilities. The signal-conditioning block has been reduced in cost and dimensions through the use of software routines for thermal compensation. The measured variables are temperature, turbidity, pH, dissolved oxygen and electrical conductivity. There are several services offered to the user, such as e-mail alarm notifications, automatic storage of measured data in a remote machine via the FTP protocol, dynamic generation of HTML reports, real time graphs and indicators visible from a remote web browser, etc. The whole system supports several types of computers, operating systems and communications hardware.