⚡ 52 engineers already in early access · Lock in £89 before the price rises to £129 · Reserve your place →

Early Access Open — App in Development

You've Done This Job for Years.
Don't Let the Theory Paper
Catch You Out.

POSISYS™ is the world's first dedicated mobile study app for Ex01–Ex04 Gas & Vapours hazardous-area preparation — built by a Senior E&I Engineer who sat the assessment himself and got tired of watching skilled engineers fail on theory they used to know cold.

Pre-Order Now — £89 → See the App
52 engineers already in early access
Be among the first when the app launches
POSISYS™ Ex01–Ex04 · Gas & Vapours
Zone Classification Q14 / 60
Question
Which gas group classification applies to acetylene in a hazardous area?
Group IIA
Group IIB
✓
Group IIC
Group IID
🔥 5-question streak — keep going!
Study
Progress
Mock Exam
Resources
™
POSISYS™ Registered Trade Mark UK Trade Mark No. UK00004343983
💳
One-Time Payment, Lifetime Access No subscription, no renewal, ever
🇬🇧
UK Built & Owned Saving Energy Consultants Limited
5yr
Certification cycle — the exam never goes away
5-day
Assessment programme — high stakes, every time
1st
Dedicated Ex01–Ex04 mobile study app in the world
The Reality

Three Reasons Good Engineers Still Fail

The exam doesn't care how long you've been on site. The preparation options haven't changed in twenty years.

📄

Scattered Resources

Revision material exists as printed handouts from the last course, a few saved PDFs, and whatever you can remember. Nothing interactive. Nothing that shows you where your knowledge has actually drifted over five years.

🔍 No structured study path exists for this exam — until now
🎯

No Way to Find Gaps

You don't know what you don't know — until the examiner tells you. There's no diagnostic tool, no mock paper, no way to simulate the written assessment before you're sitting in that room.

⚠️ Most failures are on theory, not practical competence
⏱️

Experience Isn't Enough

Twenty years on site and you still need to know which gas group acetylene sits in, off the top of your head, under exam pressure. Theory drifts. Gas group tables blur. The written paper catches experienced engineers every single year.

💸 Resitting costs time, money, and professional credibility
The POSISYS™ Difference

Three Pillars. One App.

Every feature is built around the three things that actually determine whether you pass.

🎯

Know What You Don't Know

The adaptive engine tracks every answer. It identifies weak areas and gives you more questions on those topics — less time wasted on what you already know cold.

Adaptive questions Weak-area tracking Progress dashboard
💡

Understand It, Don't Just Memorise

Every question has a full explanation — why the right answer is right, why the others are wrong, the principle that sits behind it. Engineers who understand pass. Engineers who memorise don't.

Full explanations Referenced to standards Plain English
⏱️

Simulate the Real Thing First

60 questions. Time pressure. No hints. The mock exam puts you in assessment conditions before assessment day. Walk in having already done it once — knowing exactly where you stand.

60-question mock exam Timed conditions Instant results
POSISYS™ App

The World's First Dedicated Ex01–Ex04 Study App

Built by a Senior E&I Engineer with 20+ years in hazardous-area environments. Every question grounded in real exam knowledge. Works offline. Installs on any phone in seconds.

📱
PWA Install
No App Store
🔌
Offline Mode
Study anywhere
🎯
Adaptive
Targets gaps
⏱️
Mock Exam
60q timed
📊
Progress
See your gaps
💬
Explanations
Every question
🔄
Auto-Updated
Fresh content
🏆
Streak Track
Stay motivated
🇬🇧
UK Standards
ATEX / BS EN
Pre-Order Now — £89 Try Free Resources

POSISYS™ App

In active development. Pre-order now to lock in the early access price and be first to receive your access link.

Building Now — Early Access Available
📲 No App Store needed. Open the link on any phone, tap "Add to Home Screen" — installs in seconds. Works offline too.
Simple Process

Three Steps From Purchase to Prepared

No App Store friction, no complex setup. You're studying within minutes.

1

Pre-Order or Buy

Pay once. £89 locks in lifetime access to Ex01–Ex04 Gas & Vapours. No subscription, no renewal, no hidden fees — ever.

2

Install in Seconds

We email you the link. Open it on your phone, tap "Add to Home Screen" — done. No App Store account. Works on iPhone, Android, any tablet.

3

Study, Track, Pass

Adaptive questions. Mock exam. Weak-area feedback. Walk into the assessment having already simulated it — with real confidence this time.

What Engineers Say

Built for Engineers, Trusted by Engineers

Early access members share their experience preparing with POSISYS™.

3 weeks before resit  Â·  Zone Classification
★★★★★

"I'd been putting off studying for weeks. POSISYS flagged zone classification as my biggest gap on day one — exactly what I needed to hear. Stopped guessing, started fixing."

Mike R.
Senior Instrumentation Engineer · Aberdeen
3rd attempt  Â·  Used mock exam 3× before the day
★★★★★

"Sat the mock exam three times before the real thing. Walked in knowing exactly what to expect. First time passing in one go — after two failed attempts over the years."

James T.
E&I Lead Technician · Teesside
18 years' experience  Â·  Theory confidence was the gap
★★★★★

"The explanations behind each answer are where this earns its money. I wasn't just memorising — I was finally understanding the standard properly. That's what makes the difference on paper."

Sarah L.
Electrical Engineer · Grangemouth

* Testimonials represent early access users. Replace with verified reviews as they come in.

Pricing

Simple, Honest Pricing

Pay once. Own it forever. No subscriptions, no upsells.

🔥 Early Access Price
POSISYS™ Pro
Ex01–Ex04 Gas & Vapours — Full Access
£89 £129

One-time payment · Lifetime access · No subscription

  • ✓Complete Ex01–Ex04 Gas & Vapours question bank
  • ✓Adaptive study mode — learns your weak areas
  • ✓Full timed mock exam — 60 questions, exam conditions
  • ✓Detailed explanation on every single question
  • ✓Offline access — works without internet
  • ✓Progress dashboard & weak-area tracking
  • ✓PWA install — any phone or tablet, no App Store
  • ✓All future content updates for this module
Pre-Order Now — £89
POSISYS™ Refresh Pack
For Engineers Resitting at Year 5
£49

One-time · Add on whenever you need it

  • ✓Fresh question sets — not repeats from your first buy
  • ✓Updated content reflecting current exam standards
  • ✓Targeted refresher for returning candidates
  • ✓Same adaptive engine — pinpoints gaps fast
  • ✓Offline access included
  • ✓Not locked to year 5 — buy whenever you need it
Buy Refresh Pack — £49

Secure checkout via Stripe · Instant access email · All prices include VAT

Darren Emery M.Sc.
Senior E&I Engineer · Technical Authority · Founder, TEU
20+
Years on site
Ex01
–04 Certified
TA
Tech Authority
Built By Someone Who's Been There

Not a Training Company. An Engineer Who Built the Tool He Wished Existed.

I've sat the Ex01–Ex04 Gas & Vapours assessment myself — multiple times. Every five years the industry sends experienced engineers back through the same process, and every five years those engineers prepare alone with whatever notes they can find.

There was no dedicated study app. No way to know where the gaps were before sitting in front of the examiner. I spent 20+ years in hazardous-area environments on major UK industrial sites and got tired of watching skilled engineers fail on theory — not because they couldn't do the job, but because the preparation hadn't moved with the times.

POSISYS™ is what I'd have wanted. Built from real exam knowledge, for how engineers actually learn.

  • ✓Senior E&I Engineer with 20+ years in hazardous-area environments on major UK industrial sites including Tata Steel
  • ✓Technical Authority — responsible for engineering standards on hazardous-area installations
  • ✓Multiple Ex01–Ex04 Gas & Vapours assessments sat and passed across certification cycles
  • ✓Director, Saving Energy Consultants Limited (secl.ai) · POSISYS™ UK Registered Trade Mark UK00004343983
Get in Touch
Free Resources

Three Ways to Start for Free

No account, no email required. Useful material — on us.

📐
Free Download

Ready Reckoner

Key reference tables, gas group data, temperature classifications, and zone definitions — one printable reference sheet. The kind of thing you wish you'd had in the exam room.

Download Free ↓
📖
Free Guide

Pre-Course Study Guide

Structured coverage of the core theory areas in Ex01–Ex04. Perfect for the weeks before your course starts — or to check where knowledge has drifted since last time.

Download Free ↓
⚡
Free Quiz

Readiness Snapshot

10 targeted questions. Know exactly where your gaps are before the exam finds them. 5 minutes. Your personalised result is emailed to you — no purchase needed.

Take the Snapshot →
Questions Answered

Frequently Asked Questions

Ex01–Ex04 is the Gas & Vapours competence module within the hazardous-area assessment programme for electrical and instrumentation engineers. It covers zone classification, equipment selection, installation, inspection, and maintenance — and must be renewed every five years.
POSISYS™ is an independent study aid produced by Saving Energy Consultants Limited. It is not affiliated with, endorsed by, or approved by any certification body or assessment organisation. It is a preparation tool — not a replacement for the official assessment programme.
No. POSISYS™ is a Progressive Web App. After purchase you receive a link by email. Open it on your phone, tap "Add to Home Screen" — it installs instantly, works offline, and behaves like a native app. No App Store account needed.
This was built specifically for you. Strong practical ability, theory that has drifted over five years, not much time to revise. The adaptive engine finds your exact gaps so you don't waste time on what you already know. Most experienced candidates fail on theory, not practical — this fixes that.
As soon as the app is live, early access customers are notified first. Your £89 price is locked in permanently — the standard price rises to £129 at general release and you will never be charged the difference.
Your lifetime Pro access includes all future content updates for the Ex01–Ex04 module. When year 5 arrives, the optional Refresh Pack (£49) gives you entirely new question sets and updated material — not repeats from your original purchase. Available at any time.