17-Data acquisition systems (DAS) for hydrological measurements

Abstract

With the availability of cheap reliable micro-electronic devices, such as microprocessors, solid state devices, sensors based on new technologies and communication systems, measuring instruments have become much more capable and intelligent for use in many fields, including operational hydrology. The characteristics of these devices, such as low cost, low power consumption, high reliability, and toleration of a wide range of environmental conditions make them particularly suited for applications in operational hydrology. These instruments are capable of working unattended for long periods, usually in remote sites, far from mains electrical supply. In addition to the direct use of microprocessor technology in measuring instrumenta- tion and data transmission systems, on-site data processing and analysis is also being carried out using state-of-art intelligent instruments. Data Acquistion System (DAS) are increasingly being used for hydrological data collection and processing. These systems provide an accurate, real-time (if required) analyses alongwith data collection and transmission for applications in various hydro-meteorological studies. The chapter compiles the relevant information about various DAS and hydrometeorological sensors.