We present first results from a LOFAR census of non-recycled pulsars .
The census includes almost all such pulsars known ( 194 sources ) at declinations { Dec } > 8 \degree and Galactic latitudes | { Gb } | > 3 \degree , regardless of their expected flux densities and scattering times .
Each pulsar was observed for \geq 20 minutes in the contiguous frequency range of 110–188 MHz .
Full-Stokes data were recorded .
We present the dispersion measures , flux densities , and calibrated total intensity profiles for the 158 pulsars detected in the sample .
The median uncertainty in census dispersion measures ( 1.5 \times 10 ^ { -3 } pc cm ^ { -3 } ) is ten times smaller , on average , than in the ATNF pulsar catalogue .
We combined census flux densities with those in the literature and fitted the resulting broadband spectra with single or broken power-law functions .
For 48 census pulsars such fits are being published for the first time .
Typically , the choice between single and broken power-laws , as well as the location of the spectral break , were highly influenced by the spectral coverage of the available flux density measurements .
In particular , the inclusion of measurements below 100 MHz appears essential for investigating the low-frequency turnover in the spectra for most of the census pulsars .
For several pulsars , we compared the spectral indices from different works and found the typical spread of values to be within 0.5–1.5 , suggesting a prevailing underestimation of spectral index errors in the literature .
The census observations yielded some unexpected individual source results , as we describe in the paper .
Lastly , we will provide this unique sample of wide-band , low-frequency pulse profiles via the European Pulsar Network Database .