Dual Mode Smartphone Based Sensing for Accurate Estimation of Sulphate and Chloride in Water

A smartphone-based dual-mode sensing system for accurate and reliable estimation of sulphate and chloride level in water is reported. The designed sensor is based on the detection of transmitted modulated signal (for spectrophotometric based study) and scattered signal intensities (for turbidimetric based study) from a sample. The ambient light sensor (ALS) of the phone has been used as a detector for receiving the modulated signal for both the sensing modes of studies. The applicability of the designed tool has been realized through monitoring of sulphate and chloride ions concentrations in water. A custom-designed application has been developed to convert the sensing system into a standalone tool that converts the sensing data into a readable format. The proposed sensing system could emerge as an alternative platform which can be utilized for monitoring of other parameters of water and other media as well.