Comet IXS / IOX 225 — Review, Specs & Alternatives
The Comet IOX 225 is the compact-portable end of the Comet Group X-ray range — 225 kV constant-potential generator, lightweight head, and built for field RT on thin-wall pipe and small-bore weld inspection where the bigger 300/450 kV class units are overkill. Comet (Swiss parent of Yxlon) targets the same field-RT contractor market as Ir-192 gamma source crawlers but with X-ray contrast and no transportable radioactive material headaches. Steel penetration capability is ~25 mm — making this the right pick for small-bore process pipe, thin-wall pressure vessel headers, and aerospace structural welds [1].
Specs at a glance — Comet IXS / IOX 225
Comet IOX 225 — key specs (Comet datasheet, 2023) [1]
| Parameter | Value |
|---|---|
| kV range | 40 – 225 kV (constant potential) |
| Tube current | 0.5 – 5 mA |
| Focal spot (nominal) | 1.5 × 1.5 mm (per EN 12543) |
| Beam angle | 40° conical (panoramic option available) |
| Steel penetration | ~25 mm (1 in) practical maximum |
| Generator head weight | ~16 kg |
| Control unit weight | ~12 kg |
| Cooling | Air-cooled (forced) |
| Duty cycle | 100% at rated conditions |
| Power supply | 110/230 VAC, single-phase, 10 A |
| Operating temperature | –10 °C to +45 °C |
| IP rating | IP54 |
| Safety | Dual-circuit exposure interlock, dose-rate monitor |
| Compliance | EN 12679, ASME V Article 2, ISO 17636-1, IEC 61010 |
What this is good for
Buyer matches use case to capability:
- Aerospace MRO and structural inspection on thin-wall aluminum and steel welds under 25 mm.
- Small-bore process piping fabrication (under 4 inch nominal) where 25 mm steel coverage is sufficient.
- Field RT crews specializing in thin-wall pressure vessel headers, tube sheets, and instrument piping.
- Programs replacing Se-75 selenium gamma sources with X-ray equivalent for thin-section regulatory simplification.
Where it falls short
Honest tradeoffs:
- Steel thickness above 25 mm — use SMART EVO 300 or Bordeaux 450.
- High-volume vault-based shop RT — IOX 225 has no productivity edge over larger units in fixed install.
- Large-diameter pipeline RT where panoramic Ir-192 source crawlers cover faster.
- Programs that already have SMART EVO 300 — IOX 225 capability overlaps with SMART EVO's low-kV range.
Pros
- 16 kg head weight is the lightest in the portable industrial X-ray class — one-person handling on most jobsites.
- 1.5 mm focal spot is finer than the SMART EVO 300 (2.5 mm) — better resolution on small defects in thin-wall pipe.
- Constant-potential output gives clean spectrum and high contrast for ISO 17636-1 Class B sensitivity on thin sections.
- Wide kV range from 40 kV — covers brazed aerospace assemblies and thin aluminum welds where 300 kV units cannot get low enough.
- Comet/Yxlon US service (Akron OH) provides domestic spare parts and 5-day cal turnaround.
- Lower cost than the SMART EVO 300 ($40k vs $55k) — better budget fit for shops doing only thin-wall RT.
Cons
- 225 kV ceiling limits practical steel penetration to ~25 mm — for thicker pipe and vessels, need SMART EVO 300 or Bordeaux 450.
- Tube current limited to 5 mA — slower shot times than 8-10 mA generators on equivalent thickness.
- IP54 rating is the floor for outdoor field RT — survives splash but not heavy rain. Most jobs need a tarped enclosure.
- Smaller installed base than SMART EVO 300 — fewer used units on the resale market.
- Same regulatory profile as larger X-ray units (state registration, RSO, dosimetry) — no simpler than SMART EVO from compliance perspective.
- Field crews who already own SMART EVO 300 rarely justify a second IOX 225 just for thin work — single instrument covers both ranges.
Alternatives to consider
If this unit does not fit:
| Make/Model | Why consider it |
|---|---|
| Yxlon SMART EVO 300 | Same Comet Group family, higher kV (300) and steel range (~50 mm) — but heavier and pricier. |
| Baltograph CLD 250 | Older Bal-Tec / Andrex design at similar kV class; legacy units common in older fab shops. |
| Se-75 source gamma alternative | Portable Se-75 gamma covers 5-40 mm steel range with no power requirement — but different regulatory and image quality profile. |
Certification & code compatibility
Documented use under:
- ASME BPVC Section V, Article 2 — radiographic examination of welds
- AWS D1.1 — structural welding code RT (thin sections)
- ASME B31.3 — process piping RT requirements
- ASTM E1742 — radiographic examination practice using industrial radiographic film
- EN ISO 17636-1 — RT of welded joints with X-ray film
- EN ISO 17636-2 — RT of welded joints with DDA/CR
- EN 12679 — X-ray apparatus characterization
- IEC 61010 — safety of electrical equipment for measurement
Frequently Asked Questions
When does the IOX 225 make sense over the SMART EVO 300?
Buy the IOX 225 if your scope is exclusively thin-wall (under 25 mm steel) work and you value head weight (16 kg vs 28 kg) for genuinely portable field deployment. Aerospace MRO inspectors and small-bore process pipe shops are the typical buyers. Buy the SMART EVO 300 if your scope spans 5-50 mm steel — the SMART EVO covers all the IOX 225 capability plus thicker material on a single instrument, eliminating the need for two generators. For an inspection contractor outfitting from scratch and doing mixed-thickness work, the SMART EVO 300 is the better single-instrument choice. For a specialized thin-wall RT contractor, the IOX 225 saves weight and ~$15k upfront [1][2].
Can the IOX 225 meet ASME V Article 2 sensitivity requirements on thin pipe?
Yes. ASME BPVC Section V, Article 2 sensitivity requirements (typically 2-2T or equivalent IQI for ASME B&PV work) are achievable with the IOX 225 across its full kV range on appropriate thicknesses. For 6 mm carbon steel pipe at 130 kV / 4 mA with 600 mm SFD using Class C-5 film, expect a clear 2-2T IQI image with ~30-60 second shot time. For 20 mm steel at 200 kV / 5 mA, ~90-150 seconds. The 1.5 mm focal spot is particularly helpful on thin sections where geometric unsharpness budget is tight — ISO 17636-1 Class B sensitivity is consistently achievable [1][3].
What is the realistic delivered cost and operating cost of an IOX 225 field kit?
Generator: $40k. Tripod and cabling: $3k-$5k. Shielded enclosure or warning system: $5k-$8k. Portable DDA detector (smaller than what SMART EVO uses): $10k-$18k. Total kit delivered: $58k-$71k. Operating costs: tube life ~2,000-4,000 hours, tube replacement ~$10k. Annual EN 12679 verification: $1,000-$1,500. State licensing and RSO costs identical to SMART EVO. Total 5-year operating cost (excluding tube): $8k-$10k. With one mid-life tube replacement, 5-year TCO is roughly $80k-$90k including initial purchase [1].
Is Comet/Yxlon US service strong enough for a small contractor running one IOX 225?
Yes. Yxlon USA (Akron, OH) provides direct calibration, repair, and tube replacement service to North American customers, with typical 5-7 business day turnaround for in-shop service. Replacement tubes for the IOX 225 are stocked domestically. Phone and on-site technical support is reasonable for a small fleet — Yxlon assigns named account contacts even for single-instrument customers. The Comet/Yxlon installed base in North American RT is large enough that third-party support shops (e.g. in Houston and Edmonton) also service IOX 225 units, though OEM service is the most reliable route. For remote sites, swap-out service via a second loaner unit is available on enterprise contracts [1].
References & Standards Cited
- Comet Group, IOX 225 Portable X-Ray Generator datasheet, Rev. 2023 ↗
- Yxlon International / Comet, SMART EVO 200/300 datasheet (for comparative context), Rev. 2023
- EN ISO 17636-1:2022, NDT of welds — Radiographic testing with film
- ASTM E1742/E1742M-23, Standard Practice for Radiographic Examination
- ASME BPVC Section V, Article 2 (2023), Radiographic Examination
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Founder of NDT Connect and Atlantis NDT. 15+ years in industrial inspection across oil & gas, petrochemical, and offshore. ASNT Level III certified across five methods. Drives platform standards for the NDT Connect marketplace.