UFC 3-570-06
JANUARY 31 2003
dielectric is good. The street side of the dielectric, under normal conditions (with
cathodic protection) should be at a potential more negative than -0.85 volts DC and the
house side of the dielectric should be between approximately -0.15 volts DC and -0.45
volts DC (a difference of between 400 and 700 mV). If the dielectric is good and the
house side of the dielectric has a potential more negative than expected, another
shorted dielectric in the area should be suspected, and further investigation is required
(for example, if the house side potential reading is over -0.65, with a street side potential
the same or more negative).
7-7.1.2
If the two potential measurements are not significantly different (under 10
mV), the dielectric may be shorted and additional testing is required. The preferred
method is to use a radio frequency tester (insulated flange tester) to test that specific
dielectric (paragraph 7-7.2). Other possible methods that may or may not be conclusive
include using the pipe locator method (paragraph 7-7.3) or the power supply method
(paragraph 7-7.4).
7-24
Previous Page
