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.
Building a triple sensor board with PVC fitting costs approximately $20. (US)