H2NOW is evaluating the Proteus multiprobe technology for measuring fecal coliform levels in an urban waterway setting. This device uses a novel tryptophan-like fluorescence (TLF) sensor, along with already proven temperature, turbidity, specific conductivity, and colored dissolved organic matter (CDOM) sensors to estimate microbial levels in real-time. Proteus Instruments applies an algorithm that compensates TLF readings for the effect of changing temperature and uses turbidity, specific conductivity, and CDOM as model inputs to estimate the number of fecal coliform bacteria in the water. The model parameters are calculated on the basis of observed correlation of sensor readings to microbial lab test results and entered directly into Proteus software.

The multiprobe itself is made with stainless steel to ensure durability and utilizes a wiper arm to clean the optical sensor surfaces before each reading is taken. In H2NOW, Proteus sensor readings are obtained every 15 minutes and transmitted immediately.