Colorimetric water quality sensing with mobile smart phones

The goal of this thesis is to develop water quality sensors that are portable, low cost, easy to use, and accurate. Such technology may potentially be beneficial for a significant portion of the world's population who use ground water that is neither tested nor treated. We have developed two versions of a colorimetric water quality sensor using an approach based on integration with mobile smart phones. Mobile smart phones are advanced communication devices with features including a touch-based interface, internet connectivity, and operating systems capable of running application software (apps). Integration of these features with sensor hardware can yield a new class of sensors with augmented usability, data mobility, and general appeal. The first sensor prototype created in this work is based on a sensor attachment that physically connects to an iPhone smart phone, utilizing the flash and camera onboard the iPhone to perform colorimetric measurement of water samples. The second sensor prototype created is based on a colorimetric sensor node that wirelessly communicates with an Android smart phone through Bluetooth connection. Both sensors are capable of measuring pH and the concentrations of chlorine and alkalinity, with accuracy and precision comparable to industry-standard colorimeters. The distinguishing features of our prototypes include high portability, operation without instruction manuals by interaction with a user through a graphical interface, high data mobility by exploiting the internet connectivity of smart phones, and rapid water quality measurements.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat