  Whether large ferroelectric polarization P exists in the orthorhombic HoMnO3
with the E-type antiferromagnetic spin ordering or not remains as one of
unresolved, challenging issues in the physics of multiferroics. The issue is
closely linked to an intriguing experimental difficulty for determining P of
polycrystalline specimens that conventional pyroelectric current measurements
performed after a poling procedure under high dc electric fields are subject to
large errors due to the problems caused by leakage currents or space charges.
To overcome the difficulty, we employed the PUND method, which uses
successively the two positive and two negative electrical pulses, to directly
measure electrical hysteresis loops in several polycrystalline HoMnO3 specimens
below their N\'eel temperatures. We found that all the HoMnO3 samples had
similar remnant polarization Pr values at each temperature, regardless of their
variations in resistivity, dielectric constant, and pyroelectric current
levels. Moreover, Pr of ~0.07 \mu\C/cm2 at 6 K is consistent with the P value
obtained from the pyroelectric current measurement performed after a short
pulse poling. Our findings suggest that intrinsic P of polycrystalline HoMnO3
can be determined through the PUND method and P at 0 K may reach ~0.24
\mu\C/cm2 in a single crystalline specimen.
