On an installed floor, ASTM F150-25 section 8.3 requires a minimum of five resistance tests per floor surface material, or five tests per 5,000 ft² of floor material, whichever is greater. Its two installed-floor tests, surface to surface and surface to ground, use different electrode connections and placement.
Test area and test locations
Size of the tested portion
When flooring is tested after jobsite installation, F150-25 section 6.2 requires the tested portion of the installed floor to be an area not exceeding 20 ft by 20 ft (6 m by 6 m).
Test locations on an existing floor
For an existing floor, or one that has already had its initial test, section 8.3 recommends conducting at least three of the five tests in areas subject to wear, chemical or water spillage, or visible dirt.
Electrode placement for the two installed tests
Surface to surface (section 8.2.1)
Place the electrodes at least 1 in. (25.4 mm) in from an edge of the area to be tested and 36 in. (914.4 mm) apart. The placement is the same for conductive floors (8.2.1.1) and static-dissipative floors (8.2.1.2).
Surface to ground (section 8.2.2)
Attach the positive electrode, or the positive wire from the megohm meter, to the ground connection and place the negative electrode on the surface of the flooring material.
Frequently Asked Questions
ASTM F150-25 requires at least five tests per floor surface material or at least five tests per 5,000 ft² of floor material, whichever is greater. The portion of floor used as the specimen after jobsite installation must not exceed 20 ft by 20 ft (6 m by 6 m).
For an existing floor or one that has already had its initial test, ASTM F150-25 recommends conducting at least three of the five tests in areas subject to wear, chemical or water spillage, or visible dirt.
For surface-to-surface testing of conductive or static-dissipative floors, place the electrodes at least 1 in. (25.4 mm) in from an edge of the test area and 36 in. (914.4 mm) apart. For surface-to-ground testing, attach the positive electrode or positive wire from the megohm meter to the ground connection and place the negative electrode on the flooring surface.