December results
Justification for Product Materials
Sensor Selection
When selecting a pressure transducer is it important to consider the expected range of depth, the accuracy of the transducer, and the cost. Average well depths for this particular project range from 0-10 ft which corresponds to approximately 4.33 psi. In order to obtain accurate data, the selected pressure transducer should ideally have a maximum error no greater than 0.1%.
Because the expected range of depth is only 0-10 ft, it was decided that the pressure transducer would only need a pressure range of 0-5 psi. Due to budget constraints, a pressure transducer with 0.1% accuracy was not a feasible option. However, Dwyer Instruments produces a pressure transducer that can measure a pressure range of 0-5 psi with 0.25% for a base cost of only $115. An error of 0.25% corresponds to approximately 0.35 inches of water. The relatively low cost and high accuracy of this transducer were the deciding factor in selecting this transducer.
Mesh Network
This product design is specified to be used only for a single well tap; however, the Final Report will include discussion of a proof of concept to transfer data from multiple well taps to a single site. Each well tap will be equipped with one "satellite" case as mentioned in the Design Package and will report to a single "coordinator" case. The "coordinator" will compile and send the data from each well tap as a collective unit to an off-site source to be analyzed by the user. This proof of concept will determine an easy and practical solution to past methods of water level data collection and will conceptualize a potential future market for this product design.
Battery Selection
The batteries used in this project had to be rechargeable as well as longer lasting in order to meet the convenience factor of the project. The group wanted to make sure that the user wouldn't have to go check on battery life every few days since this device would be running on constant time intervals. Also, since the satellite and coordinator devices are not physically connected in the same electronic system, two batteries with different power output and life were used. This ensured that both systems had optimal power supplies and would maintain the devices "convenience for the user" requirement.