Virginia analog dial gage and a digital linear potentiometer

Virginia and West Virginia Water Science Center's analog dial gage and a digital linear potentiometer (blue barrel) used to measure land-surface movement in response to aquifer system deformation at the USGS Nansemond extensometer. The potentiometer is the primary instrument for the extensometer with a resolution of about 0.00001 feet (0.003048 millimeters) and a travel range of 0.328084 feet (100 millimeters). The dial gage can be read to a precision of 0.0001 inches and has a range of 1 inch.