Maxwell displacement cut-rent (MDC) measurement has been employed to study
the dielectric property of Langmuir-films, A method for determining the die
lectric relaxation time of floating monolayers on the water surface is pres
ented. MDC flowing across the monolayers is analyzed using a rod-like molec
ular model. It is revealed that the dielectric relaxation time of monolayer
in the isotropic polar orientational phase is determined using a linear re
lationship between the monolayer compression speed and the molecular area A
(m). Compression speed alpha was about 30, 30, 50mm/min.