Explosion proof camera specifications explained systems from Veilux are engineered for the most demanding hazardous environments, certified for Class I Division 1 and Zone 1 areas. Our explosion proof camera specifications explained lineup meets ATEX, IECEx, and UL standards.
Explosion-proof camera specification sheets contain two sets of data: camera performance parameters (resolution, minimum illumination, compression format) and hazardous area certification data (ATEX or NEC marking, gas group, temperature class). Both are equally important. A camera that is correctly certified but underperforms at night, or performs well optically but is certified for the wrong gas group, fails the installation in different ways.
This guide decodes each section of a typical explosion-proof camera spec sheet, explains what the numbers mean in real-world terms, and identifies the values that are most commonly misunderstood during procurement. The goal is to help engineering and procurement teams read a specification sheet as a technical document, not just a marketing checklist.
Resolution: What Megapixel Numbers Actually Mean
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Explosion Proof Camera Specifications Explained for Hazardous Locations
Resolution is specified as pixels in the format Width x Height (e.g., 1920×1080) or as megapixels (2MP = 1920×1080). Higher resolution means more detail at a given distance, or the same detail level at a greater distance. The practical significance of resolution depends entirely on the required monitoring task and the camera’s coverage angle.
A 2MP camera with a narrow 27-degree FOV (12mm lens) provides more detail per target at 50 meters than an 8MP camera with a wide 90-degree FOV at the same distance — because the 8MP camera’s pixels are spread across a much larger area. When comparing spec sheets, always evaluate resolution alongside the lens focal length and FOV. Resolution alone is meaningless without knowing what area it covers.
Minimum Illumination: What the Lux Values Mean
Minimum illumination is the lowest light level at which the camera produces a usable image. It is specified in lux (lx) for color and sometimes a separate value for black-and-white mode. Lower lux values indicate better low-light performance.
| Minimum Illumination Value | Practical Meaning | Equivalent Conditions |
|---|---|---|
| 0.5 lux (color) | Poor low-light, usable only in lit areas | Dimly lit parking area |
| 0.05 lux (color) | Good low-light for outdoor use | Facility perimeter with distant lighting |
| 0.01 lux (color) | Excellent, usable in near-dark conditions | Moonlit outdoor area |
| 0.001 lux (B&W) | Usable in starlight conditions without IR | Open area under clear starlit sky |
| 0 lux (with IR on) | Complete darkness — active IR illumination | Total blackout; IR LEDs illuminate the scene |
For hazardous area cameras without artificial lighting (such as remote tank farm perimeters), specify cameras with 0.01 lux color or better, plus built-in IR illumination. Cameras claiming “0 lux” are only usable with their IR LEDs active — they do not image a completely dark scene without the IR. Always verify the IR illumination range (30m, 50m, 100m) at the working distance required.
WDR (Wide Dynamic Range): When It Matters and When It Doesn’t
WDR allows cameras to capture usable detail in scenes with extreme contrast — bright sunlight through a dark opening, or a brightly lit process area with dark shadows. WDR is specified in decibels (dB): 60dB is basic, 100dB is good, 120dB+ is high-end. True WDR uses multiple exposures combined in hardware; digital WDR (DWDR) is software enhancement with less effective results.
In hazardous area applications, WDR is most valuable at facility entry gates (bright sky background with vehicles in shadow), offshore deck monitoring (sun reflection off the sea), and chemical loading areas where tankers create large shadows. In uniformly lit indoor process areas, WDR is less critical. Specify a minimum 100dB true WDR only where the monitoring task actually requires it — not as a blanket specification that eliminates otherwise suitable cameras.
Decoding the ATEX Marking
Every ATEX-certified camera carries a marking on the nameplate that identifies exactly what the certification covers. A typical marking reads: Ex II 2G Ex d IIB T4 Gb. Each field has a specific meaning:
Ex — certified to IEC 60079 standards (the European Ex certification prefix). II — Group II: surface industries (not underground mining, which is Group I). 2G — Category 2, Gas: approved for Zone 1 and Zone 2; remains safe with one expected fault. Ex d — Protection method: flameproof enclosure. The housing contains any internal ignition and prevents propagation to the external atmosphere. IIB — Gas group: covers IIA (propane, methane) and IIB (ethylene) gases. If the facility contains hydrogen or acetylene (Group IIC), the camera must be marked IIC, not IIB. T4 — Temperature class: maximum surface temperature 135°C. This must be lower than the auto-ignition temperature of the gases present. Gb — Equipment Protection Level b: reliable level of protection for Zone 1.
Gas group is the most commonly overlooked specification. Most petrochemical cameras are Group IIB or IIA (covering propane, methane, propylene). Facilities handling hydrogen, acetylene, or carbon disulfide require Group IIC. Installing a Group IIB camera in a Group IIC area is a compliance violation regardless of Zone rating. For a full guide to how zones and gas groups interact, see our hazardous location classification guide.
H.265 vs. H.264 Compression
Video compression format directly affects storage requirements and bandwidth. H.265 (HEVC) provides approximately 40-50% better compression than H.264 at equivalent image quality, meaning a camera recording at 1 Mbps in H.265 produces video quality roughly equivalent to 2 Mbps in H.264. For a 30-day, 16-camera system, the difference between H.264 and H.265 is approximately 20TB vs. 10TB of storage — a significant hardware cost difference.
Always specify H.265 as the minimum compression standard for new explosion-proof camera systems. Verify that the NVR or VMS can decode H.265 streams — some older VMS versions require a software upgrade for H.265 decoding. H.264 should be listed as an acceptable fallback for compatibility with legacy recording infrastructure, not as the primary specification.
Frequently Asked Questions
What resolution should I specify?
2MP for general process area monitoring. 4MP or 8MP for gate access and identification tasks. Always pair the resolution spec with the lens FOV requirement — a high-resolution camera on a wide lens provides less detail per target than a lower-resolution camera on a narrow lens.
What does T4 mean on an ATEX marking?
T4 = maximum surface temperature 135°C. Compare with the auto-ignition temperature of the gases present. If the AIT is below 135°C, a lower T-class (T5 = 100°C, T6 = 85°C) is required.
What is the difference between Group IIA, IIB, and IIC?
IIA: propane, methane (least sensitive). IIB: ethylene, H2S, common petroleum vapors. IIC: hydrogen, acetylene (most sensitive). IIC-rated cameras can go in any area; IIB cannot go in IIC areas.
What WDR rating should I look for?
100dB true WDR for high-contrast lighting applications. DWDR (digital WDR) is software-only and less effective. Don’t over-specify — 120dB WDR cameras cost significantly more and the benefit is only visible in high-contrast conditions.
H.265 or H.264?
Specify H.265 as minimum for new installations — 40-50% storage savings over H.264 at equivalent quality. Verify your VMS supports H.265 decoding before making it mandatory.
Veilux provides complete specification sheets for all camera models, including ATEX marking breakdown, performance data tested to IEC 60079 standards, and VMS compatibility lists. Request a quote and we will provide specification sheets and certificate packages for review before ordering.
Key Industry Standards and References
EPL and gas group markings are standardized in IEC 60079-0. NEC Class/Division/Group markings are in NFPA 70 Article 500. IP ratings are per IEC 60529.
Related Resources
- Explosion-Proof Camera Selection Guide
- Explosion-Proof Camera Housing Selection Guide
- IP66 vs IP67 vs IP68 Industrial Camera Ratings Explained
- ATEX Category 1, 2, 3 Equipment Guide
- Browse Explosion-Proof Cameras
- Request a Project Quote
Reading Resolution and Image Quality Specifications
Understanding resolution figures in explosion-proof camera specifications requires knowing the difference between megapixel ratings and the older television lines (TVL) standard. Megapixel values describe the total number of pixels produced by the image sensor: a 4 MP camera generates a frame of approximately 2688 x 1520 pixels, while a 2 MP (1080p) camera produces 1920 x 1080.
TVL is a legacy analogue measurement that describes horizontal resolution as observed on a test chart, and while it still appears on some datasheets for legacy CCTV integration purposes, it is not directly comparable to megapixel figures. When reviewing explosion-proof camera specifications, always use megapixel values for any IP-based system comparison.
Many datasheets cite both effective pixels and total pixels. Effective pixels represent the portion of the sensor actually used for image capture after optical correction zones at the sensor edges are excluded. Total pixels include these edge areas. For practical resolution comparisons between explosion-proof camera specifications, the effective pixel count is the only number that matters — a sensor advertising 4.1 total megapixels may only deliver 4.0 effective megapixels, but this minor difference rarely affects real-world performance.
Compression codec specifications directly affect storage and bandwidth planning. H.265 (HEVC) delivers equivalent visual quality to H.264 at approximately half the bitrate. When reviewing explosion-proof camera specifications, a camera listed at 4 Mbps H.265 is roughly equivalent in quality to an 8 Mbps H.264 stream, making direct bitrate comparisons misleading when cameras use different codecs. Always normalise to the same codec when building a storage calculation for a hazardous area NVR deployment.
Wide dynamic range (WDR) is specified in decibels. A WDR figure of 120 dB means the camera can simultaneously capture detail in scene areas that differ in brightness by a factor of one million. In practice, 100–110 dB WDR is adequate for most outdoor process plant environments, while 120 dB or above is recommended for camera positions near flare stacks, high-intensity work lighting, or doorways where the camera looks both into a dark interior and a bright exterior simultaneously. Minimum illumination figures quoted in lux should always be checked against the aperture at which they were measured — figures at F/1.2 will be optimistic compared to the actual lens supplied with the camera.
Understanding Certification Markings on Data Sheets
Explosion-proof camera data sheets carry certification marks that require careful interpretation to confirm a product is genuinely suitable for a given hazardous area. For IECEx-certified equipment, the data sheet will show a certificate number in the format IECEx [certification body] [year] X[number]. This number can be verified directly at IECEx.iec.ch, the official public database maintained by the IEC. Entering the certificate number returns the full Type Examination Certificate, the issuing body, the equipment description, the specific conditions of safe use, and the current status.
This verification step is not optional during procurement — fraudulent or misrepresented certifications have appeared in the market, and physical verification against the official database protects both the asset owner and the end user from liability.
ATEX-certified equipment carries a CE mark alongside the Ex mark and a notified body number in a hexagonal surround. The ATEX product database maintained by the European Commission allows cross-reference by certificate number, manufacturer name, or equipment description. On the data sheet, the quality assurance module letter following the certificate number indicates which conformity assessment route was used: Module B is a type examination, Module D covers production quality assurance, and the combination B+D or B+G is standard for most explosion-proof camera products.
Understanding these module codes confirms that the certification covers both the design (type examination) and the ongoing manufacturing process (quality assurance).
The Type Examination Certificate is the core certification document. It describes the specific model variants covered, the special conditions of safe use (marked as X on IECEx certificates), and the electrical and constructional parameters that define the equipment’s safety. The Declaration of Conformity is a separate manufacturer-issued document that declares compliance with the applicable directives.
Both documents should be requested from the supplier and retained as part of the facility’s equipment documentation package. IECEx certificates do not expire in the traditional sense but can be withdrawn or amended — always verify the current status of any certificate before placing a purchase order, particularly for equipment that has been in the market for several years.
Key Environmental and Mechanical Specifications to Verify
The IP (Ingress Protection) code is one of the most commonly misread items in explosion-proof camera specifications. The two digits following IP describe protection against solid particles and liquids respectively. IP66 means the enclosure is dust-tight and protected against powerful water jets from any direction — suitable for most outdoor hazardous area installations. IP67 adds protection against temporary immersion to one metre for up to 30 minutes, relevant for cameras in drainage channels or low-lying process areas.
IP68 indicates continuous immersion protection to a manufacturer-specified depth, which applies to underwater pipeline inspection cameras or submerged monitoring applications. For most surface-mounted explosion-proof cameras, IP66 is the baseline requirement; specifying IP67 or IP68 where not needed adds unnecessary cost.
Operating temperature and storage temperature are two distinct figures in explosion-proof camera specifications, and both must be verified against the site’s climate data. Operating temperature defines the range within which the camera functions correctly; storage temperature defines the range the camera can survive while powered off. In arctic or sub-arctic installations, cameras may be stored unheated during seasonal shutdowns, so the storage temperature lower limit must accommodate minimum winter ambient temperatures.
At the other extreme, cameras mounted near process heaters or in tropical climates must have an upper operating temperature limit that exceeds the maximum surface temperature the housing will reach, including solar gain.
Vibration and shock ratings are particularly important in explosion-proof camera specifications for applications on compressor structures, offshore platforms, or near heavy machinery. The relevant standard is IEC 60068-2-6 for sinusoidal vibration testing and IEC 60068-2-27 for shock testing. Data sheets should state the specific g-force and frequency range tested — a camera rated for 2 g at 10–55 Hz is more suitable for high-vibration environments than one rated for 1 g at the same frequency range. Housing material also affects long-term reliability: die-cast aluminium alloy is the standard choice for Zone 2 and many Zone 1 applications, offering a good strength-to-weight ratio, while 316L stainless steel is specified for highly corrosive environments such as offshore splash zones, chemical plants handling chlorinated compounds, or coastal locations with salt-laden air.
Weight is a practical consideration for installations on grating walkways or lightweight support structures in classified areas where structural load calculations may limit the permissible equipment mass.
As a leading provider of explosion proof camera specifications explained solutions, Veilux delivers certified equipment built for hazardous environments. Our explosion proof camera specifications explained lineup is ATEX, IECEx, and UL listed for Class I Division 1 and Zone 1 applications. Every explosion proof camera specifications explained unit undergoes rigorous testing to ensure reliable operation in explosive atmospheres.
Veilux engineers are available to help you specify the right explosion proof camera specifications explained system for your site requirements. Explore our full selection of explosion proof camera specifications explained equipment and request a custom quote today.
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About the Author
Daniel Fernandez
Daniel Fernandez is a hazardous area security systems specialist with over a decade of experience specifying ATEX, IECEx, UL Class I Division 1, and cUL certified surveillance equipment for oil and gas, chemical, mining, pharmaceutical, and offshore environments. He holds expertise in NEC and IEC area classification standards and has consulted on explosion-proof camera system designs across North America, Europe, and the Middle East.