Detecting the Invisible: The Science of Holiday Testing

Here’s a behind-the-scenes look at holiday testing, a crucial quality control step in coating inspections. The technician in this photo is inside a metal surge tank at the Orr Ditch BPS/Hydroelectric project. She is using a holiday detector to check for pinholes, cracks, or defects in the coating. Even the tiniest flaw can lead to corrosion over time, so this test ensures the protective layer is solid and continuous. Holiday testing uses high voltage to detect imperfections you can’t see—because when it comes to protection, details matter!