In　this　study,　the　regimes　of　detonation　transmission　through　a　single　orifice　plate　were　investigated　systematically　in　a　6-m　length　and　90-mm　inner　diameter　round　tube.　A　series　of　experiments　on　the　detonation　propagation　mechanisms　in　hydrogen-air　mixtures　were　performed.　A　single　obstacle　with　different　orifice　size　(d)　from　10　to　60　mm　was　adopted　to　study　the　effects　of　the　induced　perturbations　on　the　detonation　propagation.　Here,　the　thickness　of　orifice　plate　(delta)　was　fixed　at　10.33　mm.　Detonation　velocity　was　determined　from　the　time-of-arrival　(TOA)　of　the　detonation　wave　recorded　by　eight　high-speed　piezoelectric　pressure　transducers　(PCB102B06).　Detonation　cellular　size　was　obtained　by　the　smoked　foil　technique.　The　characteristic　of　detonation　velocity　evolution　were　quantitatively　analyzed　after　it　passes　through　a　single　obstacle,　and　particular　attention　was　paid　to　the　cases　for　which　the　blockage　ratio　(BR)　is　greater　than　0.9,　i.e.,　the　cases　of　small　hole　diameter　of　d　＜　25　mm.　The　experimental　results　showed　that,　in　a　smooth　tube,　only　super-critical　condition　and　sub-critical　condition　can　be　observed.　After　the　orifice　plate　is　introduced　into　the　tube,　critical　condition　occurs.　The　detonation　re-initiation　with　distinct　cellular　structures　was　experimentally　observed.　Of　note　is　that　when　the　blockage　ratio　(BR)　values　in　the　range　of　0.802-0.96,　it　was　easier　to　detonate　at　the　fuellean　side.　Finally,　the　critical　condition　for　detonation　propagation　through　an　orifice　plate　was　quantified　as　d/lambda　＞　1　where　a　is　the　detonation　cell　size.　(C)　2019　Hydrogen　Energy　Publications　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.