From spotting invisible discharge to making maintenance decisions, here are answers to ten questions we frequently hear about UV cameras. Understanding these fundamentals can help inspection teams identify potential problems earlier, interpret findings more effectively, and make better-informed maintenance decisions.
Do I need training or certification to use a UV camera?
OFIL provides free onboarding training with every camera purchase to help you get started. Formal certification is optional. If you want to expand your knowledge, the 2.5-day UVoGrapher certification course offers deeper training in corona detection, inspection techniques, interpretation, and reporting.
What can a UV camera detect that a thermal camera might miss?
UV cameras detect corona and surface discharge associated with electrical voltage stress. Thermal cameras detect temperature differences, including heating caused by resistance and current flow. Because discharge can occur without measurable heating, combining UV, thermal, and visual inspection provides a more complete picture of equipment condition.
Does detecting corona always mean something is wrong?
Not necessarily—the location matters. Discharge on an arcing horn has different implications from discharge on an insulator’s end fitting. Pinpointing the source helps distinguish activity that may be acceptable at a particular location from activity that requires further investigation.
Can corona damage equipment—or is it just a warning sign?
It can be both. Corona may indicate contamination, poor installation, sharp edges, or damaged components. It also produces ozone and acidic compounds that can deteriorate materials over time. Early detection creates an opportunity to address the cause before damage progresses.
Does a higher UV count mean a more serious problem?
A count alone is not enough to determine severity. Interpretation also requires the discharge location, component type, environmental conditions, and inspection history. Guidelines such as those developed by EPRI support this assessment and are incorporated into OFIL’s Gridnostic software to help translate inspection findings into severity levels and maintenance priorities.
How far away can you reliably detect corona?
Detection distance depends on camera sensitivity, discharge intensity, and environmental conditions. Some OFIL models support inspection distances of up to 150–200 metres under suitable conditions. A sensitivity specification such as “1 pC at 15 metres” describes a tested detection capability, rather than the camera’s maximum working distance.
Can you inspect in daylight, or do you need darkness?
OFIL’s solar-blind UV cameras work in full daylight. They detect UV emissions in the 240–280 nm band, where solar radiation is absorbed by the atmosphere. This allows inspectors to see corona on energized equipment during normal daytime inspections, without waiting for darkness.
How can a UV camera deliver a return on investment?
Its value comes from identifying developing issues early enough to take action. Targeted maintenance can help avoid equipment damage, unplanned outages, and costly replacements. The potential return depends on the equipment inspected, the consequences of failure, and how inspection findings are used in maintenance planning.
Can I put a number on the financial value of UV inspection?
OFIL’s free Financial Risk Assistant helps estimate annual financial exposure across an equipment portfolio and explore the potential value of an OFIL camera. Users can adjust inputs and generate an executive report. The results are planning estimates based on assumptions, rather than guaranteed savings or payback.
You’ve found corona. What should you do next?
Document the exact location, capture images or video, and record the inspection conditions. Assess the finding alongside visual and thermal evidence, equipment criticality, and previous results. OFIL’s Gridnostic software and our Professional Services team can help interpret the findings and determine whether the next step should be monitoring, further investigation, or corrective maintenance.
