The Elcometer 236 DC Holiday Detector The premature corrosion of a substrate is often due to the failure of its coating. Major causes of failure are flaws in the finished coating, these include pinholes, holidays, inclusions, thin spots and bubbles. The Elcometer 236s convenient carry case allows the probe handle and accessories to be attached to the front making the Elcometer 236 ideal for field, site or laboratory nspection. Each unit provides the user with complete control on Voltage and Sensitivity settings. The Elcometer 236 minimizes the risk of additional damage to a coating and avoids the danger of coating popping off the surface which can occur with some high Voltage systems.