This paper explores the development of a low-cost instrument using a similar architecture to a one-port vector receiver intended for estimating Arsenic (As) ions diluted in water. The instrument is implemented with modular off-The-shelf-components. The measurements are performed with the designed prototype connected to a dielectric assessment kit 3.5 from Schmidt Partner Engineering AG and are compared for different levels of Arsenic solved in water. The preliminary results obtained are promising to continue the study of this instrumentation and pave the way to develop further sensor and instrumentation for water-sensing and monitoring applications. © 2020 IEEE.