Pictured at right is a closeup of the inside of the tipping-bucket gauge. The black object in the center of the gauge is a two-sided bucket mounted on a fulcrum halfway between the two buckets. As precipitation collects in one side of the bucket, it eventually tips the bucket, activating a contact switch in the process. Then, the other side of the gauge fills, and the bucket tips back, and so forth. Each switch activation is recorded by the datalogger and stored on the departmental UNIX system.
Spent water drains out the bottom of the gauge.
The pressure sensor used here is a Setra Model 276 pressure transducer. The Wind Mark IIIa wind sensor measures the wind speed and direction with separate sensors. Wind speed is measured with the three-cup anemometer pictured above. The frequency is proportional to wind speed. We have thus far only undertaken rough calibration of the wind direction, so there may be an error of up to 20 degrees in our currently reported values.