The design and application of an inexpensive pressure monitoring system for shallow water level measurement, tensiometry and piezometry

The measurement of water level or pressure is often a key requirement in the study of hydrogeological, hydrological and soil science processes. Modern microelectronics can provide a range of solutions for the automated monitoring of water levels in boreholes, rivers as well as more specialised applications such as tensiometry. The advantages of stand-alone monitoring systems when compared to manual measurement approaches are well understood, especially when the point of measurement is remote or the frequency of perturbation is rapid. For this reason the combination of a pressure transducer and logging system within a single package has been widely adopted in commercially available systems. However, although the price of these devices continues to fall, they may still represent a significant cost for researchers on limited budgets. We therefore present a design for a simple, inexpensive (∼£30) but versatile pressure monitoring system which can interface to low-cost (£50–£70) data-loggers. We demonstrate how the design may be adapted for a range of field applications which include: river level measurements, tensiometers, permeameters and in situ river-bed piezometers. The performance of the system is assessed and for each application the specific design and examples of resulting data are described.