For environmental monitoring it is often desirable to have in-situ measurements with high temporal resolution. The traditional approach is to deploy a measurement instrument into a water body. which allows measurement at a single point. lt is often desirable to have measurements at multiple points to understand the spatial variability of the system under study. Using the traditional approach this is not usually possible due to the high cost of such a system.

This paper describes an approach to overcome this problem by selling up a sub-sampling chamber containing a single set of water quality sensors that can take samples from multiple sources. The system uses an array of valves to select the desired sample point. and a peristaltic pump to deliver the sample to the measurement sensor array. Being able to use a single set of water quality sensors to automatically test multiple sampling points has the advantages of being cost effective, less prone to contamination and calibration procedures can be simplified and made safer in hazardous monitoring environments.