  We present the application of a fast quasi-adiabatic continuous method to the
measurement of specific heat at 4He temperatures, which can be used for the
study of a wide range of materials. The technique can be performed in the same
configuration used for the relaxation method, as the typical time constants
between calorimetric cell and thermal sink at 4.2 K are chosen to be of the
order of tau~30 s. The accuracy in the absolute values have been tested by
comparing them to relaxation-method results obtained in the same samples
(performed in situ using the same set-up), with a deviation between the
absolute values < 3% in the whole temperature range. This new version of the
continuous calorimetric method at low temperatures allows us to completely
characterize and measure a sample within a few hours with a high density of
data points, whereas when employing other methods we typically need a few days.
An exhaustive study has been performed for reproducibility to be tested. In the
present work, we have applied this method to two different substances: CeSb2,
which exhibits three magnetic transitions at 15.5 K, 11.7 K and 9.5 K, and
graphite, both highly-oriented pyrolytic graphite (HOPG) and natural crystals.
Our results on these graphites are discussed in comparison with previous
published data on different kinds of graphite samples.
