  We present a polarimetric analysis of 49 long-period pulsars discovered as
part of the High Time Resolution Universe (HTRU) southern survey. The sources
exhibit the typical characteristics of "old" pulsars, with low fractional
linear and circular polarisation and narrow, multicomponent profiles. Although
the position angle swings are generally complex, for two of the analysed
pulsars (J1622-3751 and J1710-2616) we obtained an indication of the geometry
via the rotating vector model. We were able to determine a value of the
rotation measure (RM) for 34 of the sources which, when combined with their
dispersion measures (DM), yields an integrated magnetic field strength along
the line of sight. With the data presented here, the total number of values of
RM associated to pulsars discovered during the HTRU southern survey sums to 51.
The RMs are not consistent with the hypothesis of a counter-clockwise direction
of the Galactic magnetic field within an annulus included between 4 and 6 kpc
from the Galactic centre. A partial agreement with a counter-clockwise sense of
the Galactic magnetic field within the spiral arms is however found in the area
of the Carina-Sagittarius arm.
