1. Pipeline Current Mapper PCM
Radiodetection PCM
Pipeline Current Mapper PCM
Electromagnetic AC attenuation and ACVG

2. PCM Application PCM will find: Coating defects (holidays)
Radiodetection PCM
PCM Application
PCM will find:
Coating defects (holidays)
Shorts to other structures

3. Transmitter High power output (150 Watts) Very low frequency to
Radiodetection PCM
Transmitter
High power output
(150 Watts)
Very low frequency to
increase range
reduce coupling to other services
reduce field distortion

4. Transmitter Powered from a transformer/rectifier site.
Radiodetection PCM
Transmitter
Powered from a transformer/rectifier site.
From either rectified DC (20 – 50 V) or 110/240 VAC.

5. PCM Receiver Identifies signal from Transmitter Converts to Current
Radiodetection PCM
PCM Receiver
Identifies signal from Transmitter
Converts to Current
Log to 400 records and download to PC
Connect to GPS

6. A-frame Pinpoint holidays Known as ACVG ...but SAME results as DCVG.
Radiodetection PCM
A-frame
Pinpoint holidays
Known as ACVG
...but SAME results as DCVG.

7. Transmitter Connection
Radiodetection PCM
Transmitter Connection
Typical Transmitter to pipe connection
Provides a perfect pipe connection point
Anode provides perfect ground connection point

8. Transmitter Connection
Radiodetection PCM
Transmitter Connection
Disconnect Rectifier
Use same connections to connect the PCM transmitter

9. Transmitter Connection
Radiodetection PCM
Transmitter Connection
Always direct connect
Always use an independent ground
- Anode Bed
- Ground Stake
- Across an insulator?
Always have a map of the facility
Never use another utility as the ground return.
Never assume anything.

10. - First signal loss may not be the short.
Radiodetection PCM
Locating Shorts
- First signal loss may not be the short.
- There may be more than one short.
- There may be an unknown source.
Locating Coating defects
- Take readings at the same intervals.
- Make sure PCM and boot is perpendicular to the pipe.
- Hold unit steady and upright when reading current.
You do not always have to connect closest to the suspected short or coating defect.
More is not always better.

11. Setting the Transmitter
Radiodetection PCM
Setting the Transmitter
Three settings available
ELF (4+98 Hz)
ELF + CD (8 Hz)
LF (512 H z) + CD
Normal set to ELF + CD

12. Setting the Transmitter
Radiodetection PCM
Setting the Transmitter
Set Current switch to desired current

13. Taking Current Readings
Radiodetection PCM
Taking Current Readings
If ELF and arrows selected on Tx then select ELF on the RX
Locate pipe in conventional way

14. Taking Current Readings
Radiodetection PCM
Taking Current Readings
Hold the Receiver Steady on the ground and press the PCM Key.
Current is displayed after ~ 4 s

15. Taking Current Readings
Radiodetection PCM
Taking Current Readings
Unit automatically performs steps:
narrow band signal processing measures 4 Hz signal (magnetometer);
proceed to calculate depth (twin aerials);
calculate current;
determine CD (using 4 Hz + 8 Hz shift).

16. Current Direction Indicates which direction the Current is flowing
Radiodetection PCM
Current Direction
Indicates which direction the Current is flowing
Aids fault analysis

18. Methodology using PCM for Current Surveys
Radiodetection PCM
Methodology using PCM for Current Surveys
Use an independent ground and try to mimic your CP circuit when possible
Make sure rectifiers are not influencing the signal (turn off AND disconnect if necessary)
Isolate your circuit whenever possible (disconnect bonds for better surveys)
Take readings at equal distances and record your distances
Every 50 feet is a good standard (others can be used dependant on location)
Use it as a macro tool and depth of cover tool (use A-frame for micro)
Look for anomalies with more than a 5% change normally
Make sure unit is upright and perpendicular to the pipe
Use the peak mode. Check peak and null readings and verify depth when readings are suspect.
Take multiple readings in one location if you suspect the accuracy.
Know what is in the area of your pipe and what it is connected to it

19. Datalogging 400 records can be stored. Records can be:
Radiodetection PCM
Datalogging
400 records can be stored.
Records can be:
reviewed on PCM
downloaded to a PC
Records can be viewed on Excel

20. Radiodetection PCM
Datalogging

22. Radiodetection PCM
A-frame

23. Radiodetection PCM
A-frame

24. PCM with A-frame for Alternating Current Voltage Gradient Surveys
Radiodetection PCM
PCM with A-frame for Alternating Current Voltage Gradient Surveys
Used as a micro and a macro survey tool
Can be used in various soil conditions but ground contact of the probes will affect the readings
Rectifiers generally do not influence the ACVG survey
In areas of high interference or where current survey does not give you answers, ACVG can still be used with more success
Know what is in the area of your pipe and what is connected to it
Larger holidays can mask smaller ones until the larger holidays have been repaired
PCM displays A-frame readings in db or decibels. Remember every 10 db higher is twice as large
Metal to dirt contact and soil resistance (not necessarily size of holiday) is what affects the db readings

25. ACVG Methodology Radiodetection PCM
Use an independent ground and try to mimic your CP circuit when possible
Take readings parallel and along the pipe. When you see an arrow reversal go perpendicular to the pipe and make sure arrow reverses over pipe
You do not have to be right on top of the pipe when surveying
On concrete and asphalt use wet sponges or rags on the probes or wet the ground around the probes.
Take readings at equal distances usually about every two to three steps
Use the largest db reading seen around the anomaly for you records
Record all faults seen with db readings and footages or GPS coordinates.
Once done, anomalies can generally be categorized into 4 areas
80db – 100db – large
65db – 80db – medium
50db – 65db – small
50db and below – very small
LOCAL CONDITIONS DETERMINE WHAT IS A DIG!

26. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

27. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

28. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

29. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

30. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

31. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

32. Graphing in Excel and Data Interpretation
Radiodetection PCM
Graphing in Excel and Data Interpretation

33. Radiodetection PCM