Band-integrated fluxes and ratio of scattering time in the middle of HBA (left y-axis) and LBA (right y-axis) bands to the pulsar spin period for all sources detected in HBA census (red dots). Green circles mark the pulsars selected for the follow-up with LBAs. Scattering time is estimated with the Galactic electron density model from Yao et al. (2017) and scaled to respective frequencies with an exponent, α = −4.0 in τ_sc ∼ ν^α.