CompEx Ex12 (Application Design Engineers)

Attain Excellence with ELECExam

Premium Practice Questions

What is the CompEx Ex12 (Application Design Engineers)?

The CompEx Ex12 (Application Design Engineers) is the industry-leading global certification for engineers responsible for the design, selection, and application of electrical installations in explosive atmospheres. Unlike the technician-level Ex01-Ex04 modules which focus on installation and maintenance, the Ex12 module is specifically tailored for those who create the specifications and design the systems that must operate safely in hazardous areas.

  • Official Exam Name & Acronym: CompEx Ex12 Design & Applied Science (Application Design Engineers).
  • Conducting Body/Authority: The CompEx Scheme is developed and managed by JTLimited, a UK-based non-profit organization. It was established in the wake of the Piper Alpha disaster (1988) to standardize competency in hazardous environments.
  • Purpose of Exam: Professional Certification. It validates that an engineer possesses the technical knowledge to design systems that comply with international safety standards, preventing ignition sources in environments with flammable gases, mists, or dusts.
  • Geographic Validity: Recognized globally. It is the gold standard in the UK, European Union (under ATEX directives), the Middle East, Australia, and is increasingly adopted in North America as an equivalent to local hazardous area competency standards.
  • Level of Competence: Specialist/Executive Level. This is an advanced qualification intended for senior engineers and designers, not entry-level personnel.
  • Brief History: Established in the early 1990s, the CompEx scheme has evolved from a UK-centric offshore requirement to a global benchmark. The Ex12 module was introduced to bridge the gap between “installing” equipment and “designing” the systems those installations are based upon.

Who Can Take the CompEx Ex12 (Application Design Engineers)? (Eligibility Requirements)

Because Ex12 involves complex calculations, equipment selection, and interpretation of international standards (IEC 60079 series), the eligibility requirements are stringent. Candidates must demonstrate a high level of prior technical knowledge.

Eligibility Checklist

  • Academic Requirements: Minimum of a Higher National Certificate (HNC), Higher National Diploma (HND), or a B.Eng/B.Sc degree in Electrical, Electronic, or Control Engineering. Equivalent international qualifications are accepted.
  • Experience Requirements: At least 3–5 years of demonstrable experience in electrical design or project engineering within an industrial context.
  • Documentation Checklist:
    • Original academic transcripts and degree certificates.
    • A detailed CV highlighting design experience in hazardous areas.
    • Valid government-issued ID (Passport or National ID Card).
    • Employer’s endorsement or a professional reference letter.
    • Two recent passport-sized photographs (35mm x 45mm).
  • Language Proficiency: The exam and course are typically conducted in English. Candidates should have a proficiency level equivalent to IELTS 6.5 or CEFR B2 to ensure they can interpret the complex technical standards used during the assessment.
  • Age/Citizenship: Candidates must be at least 18 years old. There are no specific nationality constraints.

Summary of Eligibility

Requirement Minimum Standard
Education HNC/HND or B.Eng in Electrical/Electronic Engineering
Work Experience 3+ Years in Engineering Design
Language English (IELTS 6.5 equivalent)
Documentation Degree, CV, ID, and Employer Reference

How to Register for the CompEx Ex12 (Application Design Engineers)

Exam Schedule & Availability

  • Frequency: Courses and exams are held on-demand through authorized training providers. In major hubs (UK, Dubai, Singapore, Houston), sessions run 1–2 times per month.
  • Registration Windows: Applications typically close 14 days before the course start date to allow for document verification.
  • Scheduling: Candidates choose a specific 4-day or 5-day block that includes both the training and the assessment.

Exam Fees (Estimated)

Fee Category Estimated Cost (GBP) Estimated Cost (USD)
Course & Assessment Fee (Standard) £1,400 – £1,800 $1,750 – $2,250
CompEx Registration/Certification Fee Included in course fee Included in course fee
Rescheduling Fee £150 – £300 $190 – $375
Retake Fee (Theory Only) £250 – £400 $315 – $500

Note: Prices vary significantly by training center and region.

Booking Process

  1. Find a Center: Locate a licensed CompEx provider (e.g., Roxby, Intertek, or AIS Training).
  2. Submit Credentials: Provide your CV and degree certificates for pre-approval.
  3. Payment: Pay the full fee to secure your slot.
  4. Confirmation: Receive the “Joining Instructions” and the CompEx Toolbox Guide.

Retake Policy

  • Waiting Period: Candidates who fail the theory or design assignment can usually retake after a 4-week cooling-off period.
  • Maximum Attempts: There is no hard limit on attempts, but most centers require remedial training after three failed attempts.

Score Validity

The CompEx Ex12 certificate is valid for 5 years. To maintain the qualification, candidates must attend a refresher course and pass a recertification exam before the expiry date.


CompEx Ex12 (Application Design Engineers) Exam Format & Structure

Exam Format

  • Delivery: Mixed. It includes a Computer-Based Test (CBT) for theory and a paper-based/software-based Design Assignment.
  • Proctoring: In-person at an authorized CompEx training center.

Timing & Duration

Section Duration Format
Theory Examination 90 – 120 Minutes Multiple Choice (60 questions)
Design Assignment 3 – 5 Hours Practical Design Project
Total Course Duration 4 – 5 Days Training + Assessment

Syllabus & Content Domains

Domain Topics Covered Weightage
Standards & Regulations IEC 60079-14, ATEX Directives, DSEAR 20%
Area Classification Gas/Dust Groups, Temperature Classes, Zoning 15%
Equipment Selection EPLs, Protection Concepts (Ex d, e, i, p, n, t) 25%
Intrinsically Safe Design Zener Barriers, Galvanic Isolators, Descriptive System Documents 20%
Installation Design Cable Entry Systems, Earthing, Bonding, Protection 20%

How is the CompEx Ex12 (Application Design Engineers) Scored?

  • The Passing Threshold: The passing score is 80% for the theory exam and a 100% “Competent” rating for the design project. CompEx maintains high standards because safety is critical.
  • Negative Marking: There is no negative marking.
  • Sectional Cut-offs: You must pass BOTH the theory exam and the design assignment. Failing one requires a retake of that specific section.
  • Result Declaration: Results are usually processed by JTLimited within 4 to 6 weeks after the exam date.

How Difficult is the CompEx Ex12 (Application Design Engineers)?

Difficulty Assessment

Rating: Very Difficult. Ex12 is widely considered the most intellectually demanding module in the CompEx suite. It requires not just memorization, but the ability to apply complex engineering principles to real-world scenarios.

Historical Pass Rates

Metric Estimated Percentage
First-time Pass Rate 65% – 70%
Overall Pass Rate (after retakes) 85%

Most Challenging Topics

  • IS Loop Calculations: Calculating the compatibility of Zener barriers with field devices (L, C, and R parameters).
  • Cable Gland Selection: Navigating the selection flowcharts in IEC 60079-14.
  • Temperature Class Rating: Correctly derating equipment for high ambient temperatures.

CompEx Ex12 vs. Similar Certifications

Feature CompEx Ex12 IECEx CoPC (Unit 001/004/006) ISA/IEEE HazLoc Exam
Conducting Body JTLimited (UK) IECEx (Global) ISA (USA)
Format Course + Exam Exam Only (Usually) Exam Only
Focus Practical Design Standard Compliance US NEC 500/505 Standards
Validity 5 Years 5 Years Lifetime (usually)

When to Choose CompEx Ex12?

Choose Ex12 if you are working on projects involving ATEX (Europe) or IEC 60079 standards. It is the preferred qualification for EPC (Engineering, Procurement, and Construction) firms operating in the North Sea, Middle East, and Southeast Asia.


How to Prepare for the CompEx Ex12 (Application Design Engineers)

Recommended Study Timeline

  • Total Preparation Time: 40–60 hours of pre-study + 4 days of classroom training.
  • Study Breakdown:
    • Weeks 1-2: Thoroughly read IEC 60079-14 (Design and Selection).
    • Week 3: Practice Intrinsic Safety (IS) calculations and barrier selection.
    • Week 4: Review the CompEx Toolbox Guide.

Best Study Resources

  • The CompEx Toolbox Guide (Publication 214): The “Bible” for the exam.
  • IEC 60079-14: The core standard for design and selection.
  • EEMUA Publication 186: A practitioner’s guide to hazardous area installations.

What to Expect on CompEx Ex12 Exam Day

  • Check-in: Arrive 30 minutes early. You must present your original ID.
  • Permitted Materials: Ex12 is typically Open Book. You are allowed to use the CompEx Toolbox Guide and provided copies of relevant standards.
  • Prohibited Items: Mobile phones, programmable calculators (unless cleared), and outside notes.
  • Atmosphere: The design assignment is intense and requires high concentration. You will be provided with drawing tools and a non-programmable calculator.

After Passing the CompEx Ex12 (Application Design Engineers)

Upon passing, you will receive a JTL CompEx Certificate of Core Competence. This credential significantly boosts your career prospects:

  • Career Roles: Senior E&I Design Engineer, Hazardous Area Consultant, Project Manager (Oil & Gas/Chemical), Lead Safety Engineer.
  • Salary Impact: Certified engineers often command a 15–25% salary premium over non-certified peers.
  • Digital Badge: You can display your CompEx digital badge on LinkedIn and professional proposals.

Frequently Asked Questions

  1. Is Ex12 harder than Ex01-04? Yes, it is more theoretical and requires a much higher level of mathematical and engineering logic.
  2. Can I take Ex12 without having Ex01-04? Yes, if you meet the academic and professional design experience requirements.
  3. Do I need to be a Chartered Engineer (CEng)? No, but it is highly recommended.
  4. Is the exam based on NEC or IEC? It is primarily based on the IEC 60079 standards (Zone system).
  5. How long does the certificate last? 5 years.
  6. What happens if I fail the design assignment but pass the theory? You only need to retake the design assignment.
  7. Is there a remote version of the exam? Generally no; it requires physical presence due to the practical design assignment.
  8. What is the most common reason for failure? Incorrect Intrinsic Safety (IS) loop calculations.
  9. Can I use my own copy of IEC 60079-14? Usually, the center provides clean copies to ensure no “cheat sheets” are hidden inside.
  10. Is this recognized in the USA? Yes, as an equivalent to competency required under NEC 505.

Loading study notes...

Loading flash cards...

Loading mindmap...

Loading premium content...

Achieve a Competitive Edge in Your Electrician Exam

Master your Electrician Exam with the top study resource on the market

Complete Compatibility for All Devices

Gain unrestricted access to practice questions anytime and anywhere you require. ELECExam operates effortlessly across all mobile devices, laptops, and electronic gadgets.

Invest in the Ultimate Resource for Success

Every practice question, study note, and mind map is carefully crafted to help candidates like you conquer the Electrician Exam with ease.

Why ELECExam Is The Top Choice For Electrician Exam

Comparison Table
Features ELECExam Benefits Competitors Self Study
Exam Explanations
Green Tick
In-depth insights paired with essential exam expertise
Red Cross
Brief correct/incorrect answers only
Red Cross
Nil
Study Notes
Green Tick
Concise key notes for quick concept mastery
Red Cross
No study notes provided
Red Cross
Self prepared
Audio Study Material
Green Tick
More than 3 hours of detailed video study notes for convenient learning anytime
Red Cross
No video study materials
Red Cross
Nil
Mind Mapping
Green Tick
Organized mind maps for an in-depth understanding of the subject
Red Cross
No mind mapping tools
Red Cross
Nil
Question Bank
Green Tick
Comprehensive question database utilizing spaced repetition to enhance memory retention
Red Cross
Limited question bank
Red Cross
Nil
Device Compatibility
Green Tick
Full support for mobile, desktop, and tablet devices
Red Cross
Desktop only
Red Cross
Nil
Content Updates
Green Tick
Regular updates by dedicated exam experts
Red Cross
Infrequent updates
Red Cross
Nil
Account Access
Green Tick
Instant access upon payment completion
Red Cross
Manual account activation required
Red Cross
Nil
Success Guarantee
Green Tick
Unlimited access renewal until you succeed in the Electrician Exam within a year
Red Cross
Limited guarantee with conditions
Red Cross
Nil
Bonus Content
Green Tick
Career development resources including resume writing, productivity, and mindset training
Red Cross
No bonus content
Red Cross
Nil

One Year Success Guarantee

ELECExam provides industry-leading success rates and outstanding support for your Electrician Exam certification path. Earning the Electrician Exam certification transforms your professional standing, boosting your credentials on LinkedIn and email signatures while creating new opportunities for career growth and increased industry recognition.

We respect your dedication to professional development by offering thorough assistance throughout your Electrician Exam preparation. Our faith in our program is supported by a comprehensive one-year guarantee.

If you require additional preparation time, encounter unexpected obstacles, or need extra guidance, we’ll extend your platform access without additional fees. Simply reach out via email or mail to request an extension.

Your achievement is our focus, and we’ve made the extension process effortless. No forms to complete, no evidence needed, and no interrogation. All requests are handled efficiently and professionally. Be part of the thousands of successful professionals who have enhanced their careers using our platform.

We fully support our promise: anyone asking for extended access will receive it promptly—no complications, no questioning, guaranteed.

Elevate Your Career with the Electrician Exam Credential

CompEx Ex12 (Application Design Engineers) (365 Days)
  • 3 Hours Video Study Key Notes
  • Instant Access
  • Study Anywere
  • Support All Devices
  • Detailed Explanation
  • Mimic Real Examination Format
🛡️ One Year Success Guaranteed
Last Updated: 20 January 2026
Number of premium questions: 3100
Payment: One-time payment (no recurring fees)
2
Team purchases show a 10% discount and let you add extra member emails at checkout.
Best Value
365 Days Access
Total: $499 USD
$1.4 USD/day
90 Days Access
Total: $249 USD
$2.8 USD/day
30 Days Access
Total: $99 USD
$3.3 USD/day
Create An Account

FAQ

Our practice questions are meticulously designed to replicate the real Electrician Exam experience. Every question comes with thorough explanations, clarifying why the correct answer is accurate and why the other choices fall short.

If you do not obtain Electrician Exam certification after utilizing our platform, we will prolong your access at no additional cost until you succeed, valid for one year from the date of purchase.

ELECExam is crafted to function seamlessly across all devices. Study with ease on smartphones, tablets, iPads, and computers using our flexible platform design.

Our questions mirror the format and challenge of the Electrician Exam while adhering to ethical guidelines. We respect the copyrights of the official body and create unique content that promotes genuine understanding rather than simple rote learning. Our focus is on developing true proficiency for enduring success.

An official invoice will be emailed to you immediately after your purchase. This invoice will contain your contact information, details about the product, the payment amount, and the date of the transaction for your records.

Why ELECExam

Our past candidates loves us. Let’s see how they think about our service

James
James Verified Buyer
"Grateful for ELECExam for their exceptional resources. The study materials were thorough and straightforward. Their emphasis on practical examples helped me grasp Electrician Exam concepts effortlessly. Every dollar spent was worthwhile - it felt like having a personal mentor leading me through the Electrician Exam."
Emily R.
Emily R.Verified Buyer
"As a full time professional, ELECExam adaptable study approach was ideal. The mobile application allowed me to study while commuting. Their extensive question bank is impressive, and the performance analytics pinpointed my areas for improvement."
David H.
David H.Verified Buyer
"I used to feel overwhelmed by the Electrician Exam, but ELECExam turned studying into a manageable and even enjoyable experience. I truly appreciate this resource."
Sophia G.
Sophia G.Verified Buyer
"Just completed my Electrician Exam with the help of ELECExam. The practice questions were tough yet reasonable. The thorough explanations clarified the reasoning behind each response. The video tutorials were particularly beneficial."
Brian K.
Brian K.Verified Buyer
"ELECExam transformed my preparation for the Electrician Exam into an enjoyable experience. The engaging quizzes and real-world case studies kept my interest high. The performance tracking tools allowed me to concentrate on the areas that required more attention. A valuable investment for sure."
Olivia C.
Olivia C.Verified Buyer
"ELECExam customer support is exceptional. Whenever I had inquiries, they replied promptly. Their study resources are thorough, and the practice exams significantly assisted me in assessing my preparedness."
Daniel E.
Daniel E.Verified Buyer
"I'm thrilled I opted for ELECExam. Their structured method for Electrician Exam preparation made the experience much more manageable. The practice questions were tough yet reasonable, and the explanations were consistently straightforward."
Sarah M.
Sarah M.Verified Buyer
"Preparing for the Electrician Exam felt daunting until I discovered ELECExam. Their organized strategy and weekly study schedules helped me stay focused. The practice questions were tough yet equipped me thoroughly. I aced the exam with flying colors."
Michael S.
Michael S.Verified Buyer
"A true game changer. The educators at ELECExam are incredibly knowledgeable. Their insights on exam strategies were essential, and the community forum provided an excellent platform for networking with fellow candidates. Achieved outstanding results."
Rachel W.
Rachel W.Verified Buyer
"After dedicating months to my studies, the ELECExam quizzes and practice exams provided the essential support I required to succeed in the Electrician Exam."
Mark A.
Mark A.Verified Buyer
"Discovering ELECExam transformed my preparation. Their study resources are precise, and the practice tests significantly boosted my confidence. The weekly webinars clarified any uncertainties I had regarding challenging Electrician Exam concepts."
Megan B.
Megan B.Verified Buyer
"I utilized ELECExam for my Electrician Exam preparation and I am extremely satisfied. Their question bank is vast, and the explanations are detailed. The practice exams significantly boosted my confidence ahead of the real test."
Ethan V.
Ethan V.Verified Buyer
"Exceptional preparation program ELECExam offers a well-structured and current curriculum. The practice assessments pinpointed my areas for improvement, and their focused review resources significantly enhanced my skills. Successfully completed the Electrician Exam with high honors."
Jessica N.
Jessica N.Verified Buyer
"ELECExam study resources are invaluable. The practice tests closely resemble the actual Electrician Exam format. Their advice on managing time during the exam proved to be particularly beneficial."
James P.
James P.Verified Buyer
"I had my doubts about online exam preparation, but ELECExam transformed my approach. Their practice questions were accurate, and the explanations clarified intricate electrician concepts. I successfully passed my electrician exam on my first attempt. The mock tests proved to be especially beneficial."
Anna L.
Anna L.Verified Buyer
"ELECExam material is invaluable. Their approach to simplifying intricate Electrician Exam frameworks into easily understandable segments is exceptional. The practice tests closely resembled the real Electrician Exam format. I couldnt have achieved this without their support."
Chris T.
Chris T.Verified Buyer
"ELECExam practice tests mirrored the actual experience perfectly. I entered the Electrician Exam with a sense of calm and assurance."
Laura J.
Laura J.Verified Buyer
"Exceptional platform ELECExam method for teaching Electrician Exam analysis is both practical and impactful. The consistent updates to study resources ensured everything remained aligned with industry developments. I successfully passed the Electrician Exam on my first try."
Jason M.
Jason M.Verified Buyer
"The practice questions on ELECExam closely mirrored the real Electrician Exam. Their study schedule template kept me organized, and the video lessons were ideal for visual learners such as myself."
Isabella F.
Isabella F.Verified Buyer
"After exploring various study resources, ELECExam stood out as the best choice. Their emphasis on the practical application of Electrician Exam principles simplified the learning process. The mobile app was ideal for reviewing material during lunch breaks."

Transform Your Future Through Electrician Exam Preparation

Conquer the Electrician Exam with Assurance

Achieve a competitive edge