A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. An explosion-proof camera that was fully compliant when installed may no longer be compliant years later — corrosion, maintenance errors, substituted parts, or modifications can quietly invalidate its certification while it continues to function normally. A post-installation certification audit is the systematic check that verifies the installation remains in the condition that its certification assumed. This guide provides the audit procedure, the documentation required, and the remediation steps when non-compliances are found.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
What a Certification Audit Verifies
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. A certification audit answers five questions for each camera in a classified area:
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
- Is the camera model still the certified model? — Camera upgrades or replacements with different models void the assembly certification
- Is the housing in certified physical condition? — No modifications, no significant corrosion, no flame path damage
- Are the cable entries certified and correctly installed? — Cable glands or conduit fittings must be certified for the zone/division and correctly torqued
- Does the certification cover the actual area classification? — Zone/division and gas group must match between the camera’s certificate and the area classification drawing
- Is documentation current? — Installation records, maintenance logs, and equipment certificates on file and retrievable
Documents Required Before Starting
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. Gather these before conducting any field audit:
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
- Current area classification drawing — confirms zone/division and gas group at each camera location
- Equipment certificate for each camera model — UL file number (check at UL’s product certification database) or ATEX certificate number (check at ATEX certified equipment registers)
- Manufacturer’s installation and maintenance instructions for each camera model
- Installation records — cable gland types, conduit type, sealing fitting locations
- Maintenance log — inspection history since installation
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. If any of these documents are missing, the audit includes a document recovery phase before field work begins. Equipment certificates can typically be retrieved from the manufacturer or test lab. Missing installation records may require field reconstruction — opening enclosures to verify cable gland types and sealing fitting presence.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
Field Audit Procedure
Step 1: Verify Certification Coverage
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. At each camera, cross-reference the nameplate data against the area classification drawing:
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
- Read the nameplate or label on the camera housing — confirm the UL file number or ATEX certificate number
- Confirm the Zone/Division and Group on the nameplate matches or exceeds the classification at this location
- Confirm the T-code on the nameplate is below the auto-ignition temperature of the gases specified in the classification document
- Record any mismatch as a Finding — do not assume “close enough” is compliant
Step 2: Verify Camera Model Identity
- If possible (through a transparent window or via the VMS), confirm the camera model installed matches the model listed on the certificate
- For housings where the camera model isn’t externally visible, cross-reference maintenance records
- If records are unavailable, note as “camera model unverified” — a detailed inspection will be required to confirm
Step 3: Physical Housing Inspection
- No cracks, fractures, or deformations to the housing body
- All housing cover bolts present — correct quantity, correct material (check nameplate or maintenance instructions for bolt specification)
- No visible drilling, welding, or machining modifications to the housing
- No paint or sealant applied to flame path areas (cover mating surface)
- Housing surface corrosion: note any corrosion and classify as (a) surface only — acceptable, (b) pitting — measure depth and record, (c) through-corrosion or structural compromise — immediate Finding
- Window intact — no cracks or chips in the viewing glass
Step 4: Cable Entry Verification
- Identify all cable glands or conduit entries on the housing
- Each cable gland must be a certified type for the zone/division — look for the certification marking on the gland body (may require cleaning corrosion to read)
- All unused entries must have certified blanking plugs installed and tight
- Conduit entries: check for sealing fittings within 18 inches (NEC) — if conduit entry is present, a sealing fitting must be visible or documented
- No improvised cable entries — holes drilled through the housing with uncertified fittings are a serious Finding
Step 5: Documentation Verification
- Maintenance log shows inspections at required frequency (at minimum annual for visual/close)
- No inspection periods longer than 18 months without documented justification
- Any repairs or part replacements in the log include the replacement part specification and verification it is equivalent to original
- Last inspection findings have been closed out
Audit Finding Classification
| Finding Class | Description | Required Action |
|---|---|---|
| Critical (C) | Immediate safety risk or compliance failure — wrong certification, housing modification, missing cable gland certification | De-energize immediately or isolate area; remediate before returning to service |
| Major (M) | Significant non-compliance requiring prompt remediation — overdue detailed inspection, corrosion approaching structural concern, missing maintenance records | Remediate within 30 days; document interim controls |
| Minor (N) | Administrative gap or early-stage issue — minor label damage, surface corrosion only, inspection slightly overdue | Remediate within 90 days; track to closure |
| Observation (O) | Good practice recommendations, not a compliance failure | Consider for next maintenance cycle; no mandatory action |
Common Findings in Existing Installations
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. These findings appear frequently in facilities that have not conducted systematic audits:
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
- Camera model substitution — Original camera failed and was replaced with a different model, often because the original was discontinued. The housing certificate no longer covers the installed camera. (Critical)
- Painted flame paths — Facilities teams repainted equipment in classified areas and unknowingly painted over housing cover mating surfaces. Paint on flame paths is a compliance violation. (Critical)
- Non-certified cable glands — Original certified glands were replaced with standard industrial glands during a repair. The replacement glands may not be certified for the zone. (Critical)
- Missing blanking plugs — Unused housing entries left open or with standard pipe plugs instead of certified blanking plugs. (Critical)
- No sealing fittings — Conduit entries without sealing fittings within 18 inches, or sealing fittings with compound levels not visible (may be unfilled). (Major)
- No maintenance records — Equipment installed but never formally inspected and logged. (Major)
- Corrosion on stainless housings — Especially in marine or chemical environments where 304 stainless was used instead of 316L. (Minor to Major depending on extent)
Remediation Approach
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. For Critical findings, the immediate action is to de-energize the affected camera (removing it from service) or confirm the area is currently non-hazardous (classified area isolated or purged). Then:
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
- Identify the root cause — was this a maintenance error, a supplier substitution, or a design gap?
- Specify the compliant replacement — correct camera model, certified cable glands, appropriate housing modification prohibition
- Document the remediation — update the maintenance record with finding, root cause, corrective action, and date returned to service
- Update maintenance procedures to prevent recurrence
Frequently Asked Questions
How do I know if my explosion-proof camera is still certified after installation?
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. A camera remains certified as long as it maintains the physical condition verified during certification: the original certified camera model is installed, no housing modifications, no flame path damage, all fasteners at original specification, and certified cable glands or conduit fittings at all entries. A post-installation audit verifies these conditions against the original certification documentation.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
How often should a full certification audit be performed?
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. A detailed inspection (most thorough audit level) should be performed every 3–5 years per IEC 60079-17, or after any change-of-use. Audit frequency should increase in corrosive or high-vibration environments. Annual close inspections and quarterly visual checks are required in addition to the periodic detailed audit.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
What documents do I need for a hazardous area camera certification audit?
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. Equipment certificates (UL file number or ATEX certificate), the current area classification drawing, installation records (cable gland types, conduit types, sealing fitting locations), and the maintenance log. If documents are missing, field verification is required during the detailed inspection.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
What happens if I discover my camera installation is non-compliant?
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. De-energize or isolate the affected camera immediately. Non-compliant electrical equipment in a classified area is a reportable safety hazard under most process safety regulations. Document the finding, engage a qualified specialist for remediation planning, and update procedures to prevent recurrence.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
Can I perform a certification audit myself?
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. Qualified in-house maintenance personnel can perform visual and close inspections. Detailed inspections requiring flame path measurements should be performed by a qualified ex-equipment specialist or a certified electrician with specific hazardous area training (CompEx or equivalent). All audit documentation should be signed with the inspector’s qualifications recorded.
For definitions of key hazardous area terms used in this guide, see the Hazardous Area Classification Glossary.
Further Resources
A post-installation explosion-proof camera certification audit verifies that every certified assembly remains in the condition required to maintain its hazardous area listing. Browse Veilux’s range of explosion-proof cameras and explosion-proof housings certified for hazardous areas. For regulatory reference, see UL hazardous location standards and OSHA Process Safety Management.
For a complete overview of all selection criteria, see the Explosion-Proof Camera Selection Guide: Complete Hub.