Desco has long been a supporter of the ESD Association and we have always encouraged our customers to purchase copies of standards and other documents published by the organization ANSI/ESD S20.20 (which is also available for free from the ESDA) specifies that compliance verification testing be per ESD TR53. This is the spec that companies should note in their written ESD control plans. ESD TR53 describes the test methods and instrumentation that can be used to periodically verify the performance of ESD protective equipment and materials. It also includes troubleshooting tips.
Currently the ESDA is offering a complimentary copy of the ESD TR53 to people that register on their website.