2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/114583An algorithm of the ensemble pulsar time based on the Wiener filtration method has been constructed. This algorithm has allowed the separation of the contributions of an atomic clock and a pulsar itself to the post-fit pulsar timing residuals. The method has been applied to the timing data of the millisecond pulsars PSR B1855+09 and PSR B1937+21 and allowed the filtering out of the atomic scale component from the pulsar phase variations. Direct comparison of the terrestrial time TT(BIPM96) and the ensemble pulsar time PT$_{\rm ens}$ has displayed that the difference TT(BIPM96) -- PT$_{\rm ens}$ is within $\pm0.4 μ$s range. A new limit of gravitational wave background based on the difference TT(BIPM96) -- PT$_{\rm ens}$ was established to be $Ω_g {\rm h}^2\sim 10^{-10}$.6 pages, 3 figures. Accepted to Chin. J. Astron. Astrophys. (ChJAA)Astrophysicstext