- The NACE-CP1-001 theory exam has 100 questions: 81 scored, 19 unscored, inside a 3-hour appointment.
- Installation and Field Measurement carries the largest weight at 40-50%, ahead of Fundamentals of Corrosion at 30-40%.
- Theory-only or theory retake costs $275; the official AMPP practice exam is a separate $35 purchase.
- After an initial fail, wait 30 days for the first retake and 4 months for any retake after that.
Exam Snapshot: The Numbers You Must Know
Before you touch a single practice question, memorize the mechanics of the exam itself. CP1 here refers specifically to the AMPP Cathodic Protection Tester (CP1) theory exam, coded NACE-CP1-001, delivered at Pearson VUE test centers. Confusing this with a differently-scoped "CP1" credential from another organization will cost you study time on the wrong material, so keep this page bookmarked as your single source of truth.
- Question count: 100 total questions - 81 scored, 19 unscored - effective per the November 2025 Exam Preparation Guide.
- Appointment length: 3 hours total, including a 4-minute nondisclosure agreement and a 6-minute tutorial before the clock really starts on content.
- Question formats: multiple-choice, multiple-response, and matching items - not just simple single-answer questions.
- Passing standard: determined by AMPP's exam-specific standard, not a flat percentage you can calculate in advance.
For a deeper explanation of how the scoring standard works and why AMPP doesn't publish a fixed cut score, see CP1 Passing Score 2026: Exactly What You Need to Pass.
Domain Breakdown at a Glance
The theory exam is built from five content domains, each with an official weight range. AMPP publishes ranges, not fixed percentages, so don't force these numbers into exact splits - treat the ranges as guidance for how much study time each area deserves.
Domain 1: Fundamentals of Corrosion (30-40%)
Covers the electrochemistry that makes cathodic protection necessary in the first place.
- Corrosion cell components and the anode/cathode relationship
- Electrolyte behavior and current flow in soil and water
- Polarization and its effect on structure-to-electrolyte potentials
Domain 2: Equipment and Equipment Management (5-15%)
Focuses on the tools testers use daily and how to keep them functioning correctly.
- Reference electrodes and their calibration
- Rectifiers, test stations, and meter selection
- Equipment inspection and maintenance responsibilities
Domain 3: Installation and Field Measurement (40-50%)
The largest single domain and the practical backbone of the CP1 role.
- Taking accurate structure-to-electrolyte potential readings
- Installing test leads, anodes, and bonds correctly
- Interpreting field data to judge protection adequacy
Domain 4: Industry Practices/Requirements (1-10%)
Ties field work back to recognized industry standards and documentation expectations.
- Recordkeeping and reporting conventions
- Familiarity with recognized CP-related standards
Domain 5: Safety (1-10%)
Smaller weight but still tested - don't skip it entirely.
- Hazards specific to cathodic protection fieldwork
- Basic safe-work practices around electrical test equipment
For a full walkthrough of every subtopic inside each domain, read CP1 Exam Domains 2026: Complete Guide to All 5 Content Areas. If you're still deciding how much overall effort this exam requires compared to other credentials, How Hard Is the CP1 Exam? Complete Difficulty Guide 2026 breaks that down further.
Fees and Registration Logistics
Fee structure is one of the most misquoted parts of CP1 prep because so many unrelated credentials share the same acronym online. Stick to these figures, which are specific to the AMPP Cathodic Protection Tester program:
| Item | Cost / Detail |
|---|---|
| Theory exam-only or theory retake | $275 USD |
| Initial theory + practical exam | Included with the AMPP course fee |
| Official AMPP CP1 practice exam | $35 USD |
| Application fee schedule | Agreement to terms and conditions only, for members and nonmembers |
| Renewal fee (every 3 years) | $295 members / $525 nonmembers |
Notice that the theory exam is only half the certification requirement - a separate hands-on practical exam must also be passed. Candidates taking the full AMPP course get both exam types bundled into the course fee, while exam-only candidates pay the $275 theory fee on its own. For a complete line-item view of every cost involved from course to renewal, see CP1 Certification Cost 2026: Complete Pricing Breakdown.
Key Takeaway
Budget for the $275 theory fee separately if you're exam-only, and factor in the $35 official practice exam as a legitimate line item, not an optional extra.
What You Can (and Can't) Bring to the Test
The theory exam is closed book, which surprises candidates who assume they can lean on their course manual during the test. Here's exactly what's allowed:
- Allowed: an exam-provided reference PDF displayed on screen, and an on-screen scientific calculator built into the testing software.
- Not allowed: your course manual, personal notes, or a personal calculator of any kind.
This means your prep needs to build fluency with the on-screen reference tool before test day - not just familiarity with the underlying formulas. Practicing with a similar interface style on a CP1-focused practice platform helps remove the friction of learning a new tool under time pressure.
Eligibility and Prerequisites Cheat Sheet
Eligibility for CP1 is described a bit differently depending on where you look. AMPP's current credential page strongly recommends the CP1 course plus 6 months of cathodic protection experience, with high-school or GED-level preparation as the baseline academic expectation. However, the formal exam guide and the live credential page don't describe the experience prerequisite identically.
- If you're taking the full course, the standard in-person format runs 5 days for 4.5 CEUs, with the practical exam administered on the final day.
- If you're planning to sit the theory exam without the course, contact AMPP directly for eligibility confirmation before you book your Pearson VUE appointment.
- Certification requirements - theory, practical, and ethics - must all be completed within 4 years.
For the full nuance on how course-path and exam-only-path eligibility differ, read CP1 Requirements 2026: Eligibility, Prerequisites & How to Qualify. And if you're still weighing whether the course or the exam-only route makes more sense for your career, Is the CP1 Certification Worth It? Complete ROI Analysis 2026 covers that decision in depth.
Retakes, Certification Life, and Renewal
Two separate clocks matter after you sit the exam: your authorization window and your certification's actual lifespan.
- Authorization: theory authorization permits one attempt within one year of approval.
- First retake: after an initial failure, you must wait 30 days before scheduling again.
- Subsequent retakes: any retake after the first requires a 4-month wait.
- Certification validity: once earned, CP1 certification lasts 3 years before renewal is due.
Renewal isn't automatic - it requires 18 months of relevant work performed during the preceding 3 years, 24 Professional Development Hours accrued at a rate of at least 8 per year across a minimum of two categories, satisfaction of the ethics requirement, and payment of the $295 (member) or $525 (nonmember) renewal fee.
Final-Week Review Plan
A generic 8-week study calendar doesn't help you a week before test day - what matters now is sequencing your last review sessions around the domains that carry the most weight. Since Installation and Field Measurement (40-50%) and Fundamentals of Corrosion (30-40%) together make up the bulk of the scored questions, your final review block should be lopsided toward those two areas.
Installation and Field Measurement
- Re-drill potential reading scenarios and test-lead installation sequences
- Review common field-data interpretation traps
Fundamentals of Corrosion
- Rebuild the corrosion cell diagram from memory
- Review polarization concepts and electrolyte behavior
Equipment, Practices, Safety
- Skim equipment calibration and maintenance rules
- Review safety hazards and industry recordkeeping basics
- Do a final timed practice set to rehearse pacing across 100 questions
If you want the full study methodology behind building toward this final week - including how to structure earlier weeks around weaker domains - see CP1 Study Guide 2026: How to Pass on Your First Attempt.
Core Technical Topics to Memorize
Beyond domain weights, here's a condensed list of concrete technical content that shows up across CP1 theory questions:
- Reading and interpreting structure-to-electrolyte potentials accurately in the field
- Reference electrode types, placement, and calibration checks
- Anode installation methods and bonding technique fundamentals
- Rectifier operation basics and troubleshooting logic
- Recognizing signs of inadequate cathodic protection from field data
- Proper use of an on-screen scientific calculator under exam conditions
- Recordkeeping conventions tied to industry practice expectations
- Basic safety hazards specific to CP fieldwork and testing equipment
This list intentionally skips deep math derivations because the exam leans on applied field judgment as much as formula recall - a distinction worth understanding when you're deciding how to allocate practice time.
If any of the terminology on this page - CP1, Cathodic Protection Tester, or the credential structure itself - is still unclear, start with the fundamentals in What Is CP1? or CP1 Meaning before diving back into domain-level study. And once you're confident in the fee structure and timeline covered above, check CP1 Exam Dates 2026: Testing Windows, Deadlines & Scheduling to lock in your Pearson VUE appointment.
FAQ
100 total questions, made up of 81 scored and 19 unscored items, per the effective November 2025 Exam Preparation Guide.
The theory exam (NACE-CP1-001) is the closed-book, computer-based test at Pearson VUE covered on this page. A separate hands-on practical exam must also be passed to complete certification, and for course-path candidates it's administered on the final day of the 5-day course.
A theory-only exam or theory retake costs $275 USD. If you already took the full course, your initial theory and practical exams were bundled into the course fee, but retakes are billed separately.
Certification lasts 3 years. Renewal requires 18 months of relevant work within the preceding 3 years, 24 PDHs (at least 8 per year across two or more categories), meeting the ethics requirement, and paying $295 (member) or $525 (nonmember).
No. The theory exam is closed book. You're limited to an exam-provided reference PDF and an on-screen scientific calculator; personal calculators and your course manual are prohibited.