NACE International Eastern Regional Conference Presented by James B. Bushman, P.E. Bushman & Associates, Inc. Corrosion Consultants – Medina, OH at the 2009 NACE International Eastern Regional Conference REMOTE MONITORING of CP FOR PIPELINES AND TANKS

REMOTE MONITORING CP FOR PIPELINES & TANKS Why use remote monitoring? Why use remote monitoring? –Save money –More accuracy –More data –Obtain readings we can’t easily take –Increased frequency of readings –Spend our time problem solving rather than meter reading

REMOTE MONITORING CP FOR PIPELINES & TANKS What do we want to read? Rectifier DC Voltage and Amperage Pipeline Potential Test Station and/or Coupon Readings Critical Bonds

REMOTE MONITORING CP FOR PIPELINES & TANKS Rectifier Voltage: 00.0 VDC Rectifier Amperage: Across shunt resistor (preferably 1 Ampere per Millivolt) Measure mVs to 0.1 mV Structure Potential With permanent (??) reference electrode On & Instant Off Interrupt Capable (with GPS Sync)

REMOTE MONITORING CP FOR PIPELINES & TANKS Rectifier AC Power: XXX volts Rectifier Temperature: Thermocouple measured in mV Read how often vs. report how often? Any Other Readings??

REMOTE MONITORING CP FOR PIPELINES & TANKS Resolution: Digital Store and Transmit Resolution – Uses A to D converter – generally uses XXXX bit resolution –12 bit resolution = 2^ 12 = 4096 segments over range –16 bit resolution = 2^ 16 = 65,536 segments over range = 0 to 4 volt range can measure to 0. 1 mV –+/- versus 0 to X –Using 16 bit resolution and +/- 4 Volt range, can only resolve to 1 mV –If I instead use 20 bit A to D converter, 1,048,576 segments over range, can read +/- 4 Volt range to 0.01 mV

REMOTE MONITORING CP FOR PIPELINES & TANKS Accuracy : Digital Store and Transmit Accuracy e.g. 0.5% of reading or 0.1% of reading ±3 digits or whatever Temperature & Environment Limits: Temperature Operating & Storage Limits for stated Accuracy & for Failure Raintight Waterproof

Power Supply Power Supply –Usually AC Powered –Rechargeable battery backup  How many hours operation while AC out?  Can send auto alarm?  Stored Data & Operating Parameters in non-volatile memory? REMOTE MONITORING CP FOR PIPELINES & TANKS

Other desirable features for Rectifiers Synchronized Interrupter Time stamp for reading Temperature monitor Output adjustment Remote download of operating and monitoring parameters Min/Max Error Reporting Alarm signals Any other suggestions?

REMOTE MONITORING CP FOR PIPELINES & TANKS Test Stations Test Stations –On Potential –Synchronized “Instant-Off” Potential –Polarization Decay (leave impacting rectifiers off for 4 or more hours?) Coupons Coupons –On Potential –Instant-Off Potential –Polarization Decay

REMOTE MONITORING CP FOR PIPELINES & TANKS Critical Bond Test Stations Critical Bond Test Stations –Current Flow in Bonds  Measure in ± mV  Measure to 0.01 mV –Coupon (both On and Instant Off)

REMOTE MONITORING CP FOR PIPELINES & TANKS Test Station Power Test Station Power –Solar/Battery –Long Life Battery

REMOTE MONITORING CP FOR PIPELINES & TANKS Acquisition of Data Acquisition of Data –SCADA –Satellite –Cellular Phone or Side Bands (Texting Channels) –Drive-By Radio –Line of Site  To high tower and then SCADA to Central Area  Unit to Unit to Central Monitor

REMOTE MONITORING CP FOR PIPELINES & TANKS Transfer/Processing/Analyzing of Data Transfer/Processing/Analyzing of Data –Who supplies software? –What kind of Analysis? –What format? –How much customization is available in preformatted form?

REMOTE MONITORING CP FOR PIPELINES & TANKS What about Reliability? What about Reliability? –Warranty  How Long?  On-Site  What is included  What is not included  What about Software Upgrades  What about Continued Support for Installed System

REMOTE MONITORING CP FOR PIPELINES & TANKS Questions Questions?