As we have both known the Protoss Archons have splash damage ability both ground and air.Here the splash damage means there is an energy reduction at multi enemy units for instance if two marines are attacking against an Archon the two of them will have different amaount of damages according to their position.The near units will have high damages while the far units will have low.We can use this ability for detecting hidden Lurkers but it needs supreme  micro gaming.If you do not have detector technology and you are playing against a lurker based Zerg player,you can use this splash ability to determine the Lurker’s location and you may kill the hidden Lurker.But you must have at least 2 Zealots to use this tip easily.Firstly determine and memorize the exact location of the burrowed Lurker by just looking the starting point of the claws of Lurker when it starts to attack your Zealot.Then seriously locate the Zealot at this point and attack your own Zealot with your Archon.The splash damage will harm the Lurker if Zealot dies locate the second Zealot by preneting the death of your Archon and continue the same process.So you will se the Lurker will die without detector observation.