An ATEX rating tells you where electrical or mechanical equipment is intended to operate when a potentially explosive atmosphere may be present. For an inspection camera, the full marking matters because "ATEX rated" alone does not tell you the approved equipment group, category, gas or dust application, protection concept, gas group, temperature class, or equipment protection level.
For buyers, the useful sequence is simple: understand the zone assigned by the facility, identify the equipment category permitted in that zone, then read the complete marking on the camera. Only after that should probe diameter, reach, articulation and image features enter the discussion.
Once the hazardous-area requirement is confirmed, the next step is matching the camera to access, reach and inspection needs. AIT covers that stage in its Explosion-Proof Borescope Selection Guide.
Quick answer: For gas and vapor hazards, Zone 0 requires Category 1 equipment, Zone 1 allows Category 1 or 2, and Zone 2 allows Category 1, 2 or 3, provided the rest of the marking also matches the atmosphere. A Category 3G camera is therefore a Zone 2 camera, not a Zone 0 or Zone 1 camera.
ATEX Starts With Two Different Questions: The Workplace and the Equipment
ATEX is often discussed as if it were one rating printed on a product label. In practice, two EU directives sit behind the framework.
Directive 1999/92/EC addresses workplaces where explosive atmospheres may occur and requires hazardous places to be classified into zones. Directive 2014/34/EU addresses equipment and protective systems intended for potentially explosive atmospheres and defines equipment groups and categories.
The employer or responsible site team classifies the area as Zone 0, 1 or 2 for gas hazards, or Zone 20, 21 or 22 for dust hazards.
Equipment Group II uses Categories 1, 2 and 3 for non-mining explosive-atmosphere applications.
Category is only one part of the decision. Gas or dust designation, protection concept, group, temperature class and EPL still matter.
ATEX Categories 1, 2 and 3 Describe the Required Protection Level
For Equipment Group II, Category 1 provides a very high level of protection, Category 2 provides a high level, and Category 3 provides a normal level of protection for the conditions defined by the directive. The categories are tied to how frequently an explosive atmosphere is expected.
Important distinction: Zone describes the classified area. Category describes the equipment protection level intended for that type of area. Do not use "Zone 2" and "Category 3" as if they are the same field on a marking.
Zone 0, Zone 1 and Zone 2 Describe How Often the Gas Hazard Is Expected
The workplace directive defines gas zones by the frequency and duration of an explosive atmosphere. Zone 0 is the highest-frequency condition, Zone 1 covers occasional presence during normal operation, and Zone 2 covers conditions where the atmosphere is not likely during normal operation and, if it occurs, persists only briefly.
For gas, vapor or mist hazards that are present continuously, for long periods or frequently. Category 1G equipment is required.
For explosive gas atmospheres that are likely to occur occasionally in normal operation. Category 1G or 2G equipment may be used.
For explosive gas atmospheres not likely in normal operation, or present only briefly if they occur. Category 1G, 2G or 3G equipment may be used.
Dust hazards use Zones 20, 21 and 22 with Categories 1D, 2D and 3D. That matters because a camera marked for gas with a "G" is not automatically approved for combustible dust with a "D".
What the Letters and Numbers on an ATEX Equipment Marking Actually Tell You
A complete marking compresses several decisions into one line. The fastest way to read it is from left to right rather than focusing only on the word "ATEX."
This is why an inspection-camera buyer should ask for the complete equipment marking, not only a statement that the camera is "ATEX certified." Two cameras can both carry ATEX-related documentation while being intended for different zones, atmosphere types or protection concepts.
Gas Group and Temperature Class Can Disqualify an Otherwise Correct Zone Rating
Getting the category and zone right is not the end of the review. Gas group and temperature class answer two separate questions: which gas grouping the equipment is suitable for, and how hot the equipment surface is permitted to become.
A correct Zone 2 category does not override an unsuitable gas group or temperature class. The full equipment marking still needs to match the actual hazardous atmosphere where the inspection camera will be used.
How the AITVS Marking Works as a Real Inspection-Camera Example
AIT VideoScope (AITVS)
AITVS is AIT's nonincendive articulating videoscope for applicable Class I Division 2 and ATEX Zone 2 inspections. Its ATEX marking is II 3 G Ex ic nA IIC T4 Gc, which places it in Equipment Group II, Category 3 for gas atmospheres with Zone 2 protection.
For hazardous-area inspection in refineries, process plants, oil and gas, or energy equipment, see AIT's guide to choosing borescopes for oil, gas and energy inspection.
The same system is UL certified for Class I, Division 2, Groups A, B, C and D in North America and is documented to MIL-STD-810G Method 511.6, Procedure I for operation in an explosive atmosphere. Those are separate qualifications and should not be treated as substitutes for the ATEX marking.
Product-fit boundary: AITVS is a Category 3G / Zone 2 instrument. It is not rated for Zone 0, Zone 1, combustible-dust Zones 21 or 22, or mining Group I applications. The facility's responsible safety or engineering team still determines the area classification.
ATEX Knowledge Changes the Camera Conversation Before Specifications Do
Inspection-camera comparisons usually start with probe diameter, insertion length, articulation or image quality. In a classified area, ATEX can reverse that order. A camera can be perfect for the inspection path and still be removed from consideration before anyone discusses resolution.
That narrows the protection category, but the buyer still needs the atmosphere type, gas group, temperature requirement and complete equipment marking.
That is not enough information. The category, G or D designation, Ex protection concept, group, temperature class and EPL tell you what the marking actually permits.
Physical fit becomes relevant only after the hazardous-area qualification has cleared the location review.
The hidden risk in hazardous-area inspection is assuming that two cameras with similar probe sizes and image quality are interchangeable because both mention ATEX. Once the complete marking is read, one may fit the classified area and the other may not. That difference can decide whether the inspection proceeds at all.
