Refinery at sunset, flare and steam on the skyline — the environments Ex01–04 is the gateway to
Purpose-built Ex01–04 Gas and Vapours preparation

Walk into your Ex01–04 assessment completely ready.

Engineers fail Ex01–04 not because they lack knowledge — but because nobody properly prepared them for what was coming. POSISYS™ is built to make sure that never happens to you.

Join the waiting list See what’s inside
Refinery skyline at sunset — the environments the qualification is built for

Breathe. You know this.

Ex01–04 is the gateway qualification for hazardous-area work — refineries, offshore platforms, COMAH-regulated chemical plants. Five days. A written paper you must pass to 70% per unit. A practical you must pass. Most candidates underestimate what is actually required until they are already in the room. Preparation is the difference.

Instrument pipework on a live process plant
What's covered

Four units. One system.

No affiliation with any assessment centre, no course to upsell. Just the four units, prepared by someone who has spent forty years in hazardous areas.

Station 01 ★

Ex01 — Zone classification & fundamentals

Zones · gas groups · T-classes

ATEX and IECEx zone classification, gas groups, temperature classes, LEL/UEL, ignition sources — all of Ex01 covered the way the written paper tests it.

Station 02

Ex02 — Equipment selection & ATEX marking

Markings · EPLs · cable glands

Protection concepts, EPLs, equipment categories, cable glands, and the full ATEX marking decode. Read any marking string accurately under time pressure.

Station 03

Ex03 — Intrinsic safety systems

IS loops · barriers · worked examples

Entity parameters, Zener barriers, galvanic isolators, IS loop design. The unit most candidates find hardest — with worked calculation examples throughout.

Station 04

Ex04 — Inspection & maintenance

Grades · IP codes · defect grading

All four inspection grades, IP rating codes, inspection forms, defect grading. Know exactly what each grade requires and when to apply it.

Every unit is covered the way the paper actually tests it — question bank, worked answers and a timed mock that finds the gaps before the assessor does. Join the waiting list →

The maths What a repeat attempt really costs
5 daysthe full assessment — written papers and practical, all four units
70%the pass mark required on every written unit — no averaging your way out
£89 oncelifetime access — the cheapest insurance against repeating course, travel and fees
Format and pass marks are set by the assessment bodies — preparation is the only variable you control.
Hazardous-area warning signage at a site gate
The cost of failing

What failing actually costs.

A failed assessment is not just embarrassing. It is operationally damaging, professionally costly, and personally demoralising.

Financial cost

Financial cost

Twice over
Read the full Ex01–04 guide →
Operational cost

Operational cost

Cannot be deployed
Read the full Ex01–04 guide →
Professional cost

Professional cost

It follows you
Read the full Ex01–04 guide →
Darren Emery M.Sc. on site in high-visibility workwear
The founder

Built by the engineer who has been where you are.

Forty years in hazardous areas.

Senior Instrument Engineer and Technical Authority. Offshore platforms, steelworks, refineries, COMAH Tier 1 and chemical plant background. Deep operational knowledge of DSEAR, ATEX and IECEx. B.Sc. and M.Sc. — Teesside University. Time-served Instrument Artificer.

“I built POSISYS™ because I have seen engineers fail assessments they were more than capable of passing — not because they lacked the knowledge, but because nobody properly prepared them for what was coming.”

Built by a field practitioner — not a training company. Independent of all assessment centres.

— Darren Emery, Oxfordshire
Is this connected to an assessment centre?

No. POSISYS™ is fully independent of all assessment centres and training providers. It prepares you for the assessment — it has no say in it, and no commercial tie to anyone who does.

What exactly do I get for £89?

The full question bank across all four units, a timed mock exam with worked answers, the ATEX marking Ready Reckoner, the Calm & Focus stress toolkit, the Pre-Study Guide, and all future updates. One payment, lifetime access, no subscription.

Who is it for?

Instrument, electrical and E&I engineers preparing for Ex01–04 Gas and Vapours — first-timers and 5-year returners alike.

Why is stress part of the preparation?

Because stress is a measurable risk factor in Ex01–04 failure. POSISYS™ includes daily practices for the preparation period and a structured assessment-morning routine.

Where are the testimonials?

There are none, deliberately. No fake testimonials. Ever. The product argues its own case — and the price rises at full launch, so early access is the honest discount.

Ex-rated instrumentation in the field — the kit the assessment is about
Early access — open now

One investment. Walk in ready.

£89 — one-time. Lifetime access. No subscription.

Full question bank — all four units

Spaced repetition (SM-2 algorithm)

Full timed mock exam with worked answers

ATEX marking Ready Reckoner

Calm & Focus stress toolkit

Pre-Study Guide (PDF)

All future updates included

Early access locks in £89. General release will be higher.

Register for Early Access →

No spam. One email when POSISYS™ opens — you can unsubscribe by replying.

Storage silo and conveyor gantries in morning light
— the gateway to every hazardous-area career —

Start preparing today.
For free.

The full Ex01–04 guide is free to read — what the five days cover, how the paper is marked, and where candidates come unstuck. One email address if you have a question, read by the engineer who built the system.

darren@tempestmedia.co.uk →