Using a Velocity or Delay Time Recorder helps ensure the quality of energetic products and that timing accessories act as expected. Problems can develop if explosives are not functioning at the expected Velocity of Detonation (VOD). A lower VOD in an explosive will cause less energy to be transferred when it is detonated, greatly impacting the burden and spacing design and resulting in an overconfined blast. Problems can also occur when the timing of accessories are not accurate. Inaccurate timings can also result in the overconfinement of a blast as well as other major problems.