CORROSION MITIGATION INSTRUMENTATION
P. O. BOX 281 SAN GABRIEL,CA91778 TEL: (626) 287-5259 FAX: (626) 287-0132
PRODUCT INSTRUCTIONS
prediction of the final polarized current requirement may be made. The CS-10 should be
operated in the continuous mode for this test with the “positive” terminal connected to the
temporary ground and the “negative” output connected to the structure.
During this test, the location with the lowest Pipe to Soil reading can be determined if the
protective current is to be installed at the same point as the test is being conducted. The low
Pipe to Soil point will be the best location for a test point to ensure that there is adequate cathodic
protection current available to the system to meet protection criteria.
SHORT IDENTIFICATION TEST
To determine if there is a short on the system, some knowledge of the CP area is required. Is the
structure bare or coated? How large is it? Has the protection level changed dramatically in a
short time? When the CS-10 is connected to the structure, as in the current requirement test, and
current is applied in the continuous mode, does it take more current than would be anticipated to
increase the protective level? If so, there is a high probability that there is a short (additional load
connected) to the protected system.
SHORT LOCATION TEST
To locate the short(s) on a protected system, the CS-10 can be connected to the structure to
increase polarization, as in the current requirement test above, but operated in the interrupted
mode. At various points on the protected structure take both “off” and “on” Pipe to Soil readings.
Subtract the “off” reading from the “on” reading and record that difference (delta V) with the
location. As you approach the short location, the delta V will decrease toward 0 and as you pass
and leave the short location, the delta V will increase again. The lowest resistance short will
usually be identified first so another test for shorts should be performed to ensure that all shorts
have been located and cleared.
INSULATOR LOCATION TEST
To determine the location of buried insulator, hook the CS-10 to the structure and a temporary
ground to increase the structure polarization and switch to the interrupted mode as in the short
location test above. Then take half cell readings until there is dramatically reduced on/off
switching. This will indicate that the location is beyond an insulator. Pinpoint location can be
completed with an Audio Frequency Locator such as Tinker & Rasor’s Models PD or Mark V
Ranger .
CASING TEST
Connect the CS-10 so that it will depolarize the casing to a temporary ground. Take initial half
cell readings of the pipe and the casing, apply a small amount of current (approx. 30 mA) and
take another set of half cell readings. If the pipe and casing are both less negative, there is
probably a somewhat low resistance path between them. However, if the pipe is slightly more
negative and the casing less negative, there maybe no short. Apply a larger amount of current
(approx. 100 mA) and take another set of half cell readings. If the pipe and casing are still less
negative, a low resistant path is still indicated. If the pipe and casing keep the same reading as
each other, the path has low resistance. If the pipe is still a little more negative and the casing
less negative, any short is of very high resistance. Additional current steps will help determine if
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