Maintenance for the week of April 22:
• PC/Mac: NA and EU megaservers for patch maintenance – April 22, 4:00AM EDT (08:00 UTC) - 9:00AM EDT (13:00 UTC)
• Xbox: NA and EU megaservers for patch maintenance – April 24, 6:00AM EDT (10:00 UTC) - 12:00PM EDT (16:00 UTC)
• PlayStation®: NA and EU megaservers for patch maintenance – April 24, 6:00AM EDT (10:00 UTC) - 12:00PM EDT (16:00 UTC)
I use the Recount add on if I want to test DPS output, I don't run it all the time, just for testing, but it is pretty simple and does what it says on the tin, I would recommend that, but as Nestor says, you will need to engage enemies to try it.
Others may say different but I usually run a dungeon with it, rather than trying it repeatedly on same enemy or mob