PART 3: PACKER TESTS
Packer tests are conducted to determine the hydraulic properties of sections of an uncased or open borehole. Packers are installed to seal off a test interval. Constant‑discharge or constant‑head tests are conducted to characterize hydraulic properties. Section 15 briefly describes packer‑test methods.

This photograph shows the installation of two packers used to isolate a section of open borehole (http://www.usgs.gov/media/images/photograph-usgs-hydrologists-and-packers-well-testing↗).