This document contains the test plan for the characterization of a set of CNT filters manufactured according to the design of two of the thermal filters, namely THF2 and THF300, in the current Athena X-IFU design, that is undergoing the instrument system requirement review (I-SRR). In particular, a set of fully representative filters has been manufactured by Ametek/Canatu using the high density CNT pellicle, bare and coated with aluminum, attached to Au plated BeCu meshes, and mounted onto aluminum frames. This document provides a brief description of test procedure, test equipment,
and schedule for each proposed characterization methodology to be performed within task 5 of the contract. For more technical details on the equipment and accuracy of the test methodology we sometimes address the previous technical notes TN2 and TN6
