Salamanders are constructed out of PVC pipe, with a watertight capsule at the top to keep the Crossbow TelosB radio above the waterline, and several PVC ports to attach sensors at different points below the waterline. The most commonly used type of sensor is the TripleSensor, which measures flow velocity, light intensity, and temperature. These sensors are attached in parallel to three wires: ground, 5V power, and data. Sensors communicate using the 1-Wire bus. A “power board” is attached to each Crossbow TelosB to allow it to communicate with the sensors. This is necessary because the Crossbow operates at 3.3V while the sensors work at 5V.
Waterproofing the sensor boards is extremely important! So is leak-checking each Salamander with pressurized air before putting it out in the field.
Instructable: Create laser-cut parts for custom sensor housings
Instructable: Build triple sensor boards for flow velocity, light intensity, and temperature
Building a triple sensor board with PVC fitting costs approximately $20. (US)
Download circuit board layout, schematic and bill of materials for TripleSensor board (Eagle format)
Download design in ExpressPCB format for the PowerBoard that connects motes to TripleSensor Boards
Instructable: Build a datalogger for your wireless sensor network