Nose-to-nose　calibration　procedure　is　used　on　the　broadband　sampling　oscilloscope　which　has　double　microwave　diodes　sampler　circuit.　Study　on　the　sampler　circuit　was　preformed　in　this　article　and　drew　the　same　conclusion　about　the　premise　that　kick-out　pulse　is　proportion　to　the　impulse　response　of　the　oscilloscope.　The　mathematic　expression　which　was　reported　in　this　article　not　only　verified　further　about　the　premise　but　also　found　that　kick-out　pulse　is　related　to　the　strobe　pulse.