Pulse Holiday Detector – Overview The Pulse Holiday Detector SPARK-1 is a device used for detecting defects such as thinning, micro holes, and cracks in dielectric coatings on metals. The principle of operation is based on the electro-spark method. A probe with an electrode connected to one pole of the voltage source scans the surface of the tested object directly along with the coating. The second pole of the voltage source from the ground connector is connected directly to the metal structure. The electronic unit fixes the gaps by the voltage between the electrode and the conductive base. Pulse Holiday Detector – Features Reliable Lightweight High capacity and long-life batteries Accurate digital voltage and sensitivity settings Sound defect signalling