Fundamentals of Corrosion
30-40%of exam
Equipment and Equipment Management
5-15%of exam
Installation and Field Measurement
40-50%of exam
Potential MeasurementsCurrent MeasurementsElectrolyte MeasurementsIsolation TestingInstallationTroubleshooting
Industry Practices and Requirements
1-10%of exam
CP CriteriaRecordkeepingSite RecordsMapsInstrument Identification
Safety
1-10%of exam
Stop WorkPPELOTOSite TrainingHazardous Materials
Quick Facts
- Exam
- NACE-CP1-001
- Identity
- CP1 Theory
- Questions
- 100 total
- Scored
- 81 questions
- Unscored
- 19 pretest questions
- Time
- 3 hours
- Delivery
- Computer-based testing
- Resources
- Limited onscreen PDF
- Result
- Pass/fail
- Certification
- Theory plus practical
Oxidation and Reduction
LEO at anode; GER at cathode
LEO: lose electrons oxidationGER: gain electrons reduction
Galvanic vs Impressed Current
Galvanic
- Natural driving voltage
- Consumable active anode
- No external power
Impressed Current
- External DC source
- Rectifier drives current
- Adjustable output
Natural drive vs powered drive
Electrical Fundamentals
- Voltage
- Electrical driving forceV
- Current
- Charge flow rateA
- Resistance
- Opposes current flowohm
- Ohm's Law
- V = I x R
- Power
- P = E x I
- Series circuit
- Current stays equal
- Parallel circuit
- Voltage stays equal
- KCL
- Current entering equals leaving
Circuit Constants
Series current same; parallel voltage same
Series: resistances addParallel: currents add
Anode vs Cathode
Anode
- Oxidation occurs
- Electrons leave
- Metal is consumed
Cathode
- Reduction occurs
- Electrons arrive
- Metal is protected
Loss vs protection
Corrosion Cell
- Anode
- Oxidation; metal loss
- Cathode
- Reduction; protected site
- Electrolyte
- Ionic current path
- Metallic path
- Electronic current path
- Oxidation
- Loses electrons
- Reduction
- Gains electrons
- Polarization
- Potential shifts under current
- Shielding
- Blocks protective current
Series vs Parallel
Series
- Current stays equal
- Voltages add
- Resistances add
Parallel
- Voltage stays equal
- Currents add
- Reciprocals add
Same current vs same voltage
CP Systems
- Galvanic CP
- Natural anode driving voltage
- Impressed current
- External DC power
- Rectifier
- Converts AC to DC
- Galvanic anode
- Consumed to protect structure
- ICCP anode
- Discharges rectifier current
- Isolation
- Confines protective current
- Coating
- Reduces current demand
- Stray current
- Unintended current path
CSE vs Ag/AgCl
CSE
- Common soil reference
- Copper sulfate electrolyte
- Portable field use
Ag/AgCl
- Common seawater reference
- Chloride environment
- Offshore drop-cell use
Soil reference vs seawater reference
Reference Picker
- Buried structure in soil→Portable CSE(Prepare contact)
- Submerged in seawater→Ag/AgCl reference(Chloride environment)
- Need fixed monitoring→Stationary reference(Verify periodically)
- Need rugged fixed cell→Zinc reference(Document conversion)
- Need comparative accuracy→Verified reference cell(Check before use)
- Reference appears unstable→Comparison cell(Inspect contamination)
Meters and Tools
- Voltmeter
- Measures potential difference
- Ohmmeter
- Measures resistance
- Multimeter
- Combines electrical measurements
- Ammeter
- Measures series current
- Clamp-on ammeter
- Measures conductor current
- Shunt
- Known low resistance
- Interrupter
- Switches current sources
- Pipe locator
- Finds buried structures
Reference Cells
- CSE
- Common soil reference0.000 V vs CSE
- Ag/AgCl 3.5%
- Common seawater reference-0.060 V vs CSE
- Pure zinc
- Rugged stationary reference-1.100 V vs CSE
- Portable reference
- Moves between readings
- Stationary reference
- Remains at location
- Porous plug
- Provides electrolyte contact
- Cell check
- Compare before fieldwork
- Cell record
- Document exact reference
Wenner Pin Roles
Outer pins current; inner pins voltage
Four equal spacesrho = 2 pi A R
On vs Instant-Off Potential
On
- Current sources operating
- Includes CP IR drop
- Shows operating condition
Instant-Off
- Sources briefly interrupted
- Reduces CP IR drop
- Approximates polarized potential
Operating reading vs polarized reading
Measurement Picker
- Need structure potential→Voltmeter plus reference(Record polarity)
- Need shunt current→Millivoltmeter plus ratio(Check direction)
- Need conductor current→Clamp-on ammeter(Verify DC capability)
- Need soil resistivity→Wenner four-pin(Equal spacing)
- Need sample resistivity→Soil box(Known geometry)
- Need soil pH→Antimony plus CSE(Compare potentials)
- Need buried alignment→Pipe locator(Conductive or inductive)
- Need offshore potential→Ag/AgCl drop cell(Record reference)
Potential Measurements
- Structure potential
- Structure versus electrolyte
- Native potential
- Before CP polarization
- On potential
- Includes operating IR drop
- Instant-off
- Reduces CP IR drop
- Depolarized potential
- After polarization decays
- IR drop
- Current times path resistance
- Drop cell
- Offshore potential measurement
- CP coupon
- Simulates coating holiday
Resistance vs Resistivity
Resistance
- Specific circuit opposition
- Measured in ohms
- Depends on geometry
Resistivity
- Material property
- Includes length-area normalization
- Wenner measures soil
Circuit value vs material property
Field Diagnostic Picker
- Need polarized potential→Synchronized interrupters(Capture instant-off)
- Cannot interrupt sources→CP coupon(Disconnect briefly)
- Suspect isolation failure→Electronic isolator(Confirm comparison)
- Suspect metallic short→Potential plus current tracing(Follow current)
- Check rectifier output→External calibrated meter(Compare panel meters)
- Check galvanic anode→Current plus open potential(Verify both)
- Suspect broken test lead→Ohmmeter continuity test(Follow safe procedure)
Current Measurements
- Shunt current
- I = millivolts x ratio
- Current direction
- Read meter polarity
- Bond current
- Measure magnitude and direction
- Rectifier voltage
- Verify externally
- Rectifier current
- Verify through output shunt
- Line current
- I = K x V
- Calibration factor
- K = test current/deltaV
- Anode current
- Confirms current delivery
Electrolyte Measurements
- Wenner method
- Four equally spaced pins
- Wenner formula
- rho = 2 pi A R
- Outer pins
- Inject test current
- Inner pins
- Measure voltage response
- Soil box
- Tests collected sample
- Collins rod
- Single-point resistivity
- Pouillet's Law
- rho = R A/L
- Antimony half-cell
- Compares soil pH
Locating and Isolation
- Conductive locating
- Direct signal connection
- Inductive locating
- No direct connection
- Isolation device
- Separates metallic paths
- Potential comparison
- Screens isolation effectiveness
- Electronic isolator
- Verifies isolation device
- Jumper bond
- Temporarily bridges isolation
- Continuity test
- Checks metallic connection
- AC mitigation
- Controls induced voltage
Installation
- Surface preparation
- Ensures sound connection
- Exothermic weld
- Attaches test lead
- Pin brazing
- Alternative lead attachment
- Test station
- Provides measurement access
- mV-drop leads
- Enable line-current testing
- Foreign crossing leads
- Enable interference checks
- Permanent reference
- Install then verify periodically
- Lead splice
- Restore electrical continuity
Basic Troubleshooting
- Galvanic anode
- Check current output
- Anode potential
- Measure open-circuit value
- ICCP anode
- Check individual current
- Metallic short
- Compare structure potentials
- Current trace
- Locates short path
- Diode
- Verify one-way operation
- Internal meter
- Compare external reading
- Unexpected reading
- Verify setup first
Field Record
Record what, where, when, how
Site conditionsInstrument identityMethod and reading
Theory vs Practical Exam
Theory
- NACE-CP1-001
- CBT question exam
- 100 questions; three hours
Practical
- Separate core exam
- Hands-on assessment
- Course conclusion
Current sheet covers Theory
Records and Practice
- CP criteria
- Use governing requirements
- Ethical records
- Accurate and complete
- Personal logbook
- Retain field notes
- System maps
- Confirm testing locations
- Site record
- Date time conditions location
- Instrument record
- Name model serial
- Abnormal station
- Document unusual configuration
- Facility records
- Maintain required history
Safety Controls
- Site procedures
- Find before work
- Safety officer
- Know responsible role
- Work permit
- Acquire required authorization
- PPE
- Match site hazards
- Stop-work
- Pause unsafe task
- LOTO
- Control hazardous energy
- SDS
- Follow handling guidance
- AC voltage
- Recognize corrosion and shock
- Medical condition
- Communicate relevant risk
- Site training
- Match task environment
Common Traps
Theory vs certification
Theory is one core exam ≠ Certification also requires practical
On vs polarized
On includes CP IR drop ≠ Instant-off reduces CP IR drop
Electrons vs conventional current
Electron flow follows electrons ≠ Conventional current runs opposite
Voltage vs current
Voltmeter connects across ≠ Ammeter enters current path
Magnitude vs direction
Shunt ratio gives magnitude ≠ Meter polarity gives direction
Portable vs stationary reference
Portable moves between sites ≠ Stationary remains installed
Course vs credential
Course completion alone insufficient ≠ All requirements earn certification
Last Minute
- 1.Confirm NACE-CP1-001 Theory identity
- 2.Remember 100 total; 81 scored
- 3.Budget three CBT hours
- 4.Treat every item as scored
- 5.Match all five domain ranges
- 6.Use provided reference PDF
- 7.Bring no personal calculator
- 8.Know Ohm and Wenner formulas
- 9.Choose reference by environment
- 10.Separate on from instant-off
- 11.Check shunt ratio and polarity
- 12.Record instrument identification
- 13.Stop work for hazards
- 14.Certification also requires practical exam
Buy on AmazonSame family resources
Explore More AMPP Certifications
Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.
More From This Family
Videos and articles for deeper review.