USGS Electric Tape Gage, Tape Ordered Seperately

The USGS Electric Tape Gage is used primarily as an inside reference gage (base gage) over a stilling well. An electric tape gage consists of an aluminum frame holding a voltmeter, a reel to hold steel tape, and a base to bolt the assembly to a tabletop. A battery of less than 6 volts is required, but not furnished.

The weight is lowered until it contacts the water surface; this contact completes the electric circuit and produces a signal on the voltmeter. With the weight held in the position of first contact, the tape reading is observed at the index provided on the reel mounting.

Tapes of varying lengths are sold separately in both metric and imperial graduations.