Colloidal Borescope

Task Description

This is an innovative technology used to determine groundwater flow and direction through obser-
vation of the movement of colloid-
al particles suspended in water (Photo 1.2). This instrument con-
sists of a charge coupled device camera, an optical magnification lens, an illumination source, and a downhole compass in a watertight stainless steel housing (Figure 1.2). The borescope is lowered into boreholes to determine the direc-
tion of depth-discrete groundwater flow within the borehole. After calibration, the instrument should be capable of yielding data that will provide the magnitude of the groundwater flow. The instrument

is approximately 60 cm long, with a diameter of 4.4 cm. The electro-
nic image is transmitted to the surface by a cable. The images are viewed on a high resolution monitor and recorded on VHS tape for further analysis. The magnified image corresponds to a 1.0 x 0.4 x 0.1 mm field of view. The flow of groundwater in the borehole is quantified by observation of the movement of colloidal particles suspended in the water. Flow direction is determined by com-
parison with the downhole com-
pass and velocity by timing the movement of particles across the field of view.

Technology Needs

The baseline technology is the standard technique used to mea-