The determination of heat capacity data with sawtooth-type, temperature-modulated differential scanning calorimetry is analyzed
using the Mettler-Toledo 820 ADSC™temperature-modulated differential scanning calorimeter (TMDSC). Heat capacities were calculated
via the amplitudes of the first and higher harmonics of the Fourier series of the heat flow and heating rates. At modulation
periods lower than about 150 s, the heat capacity deviates increasingly to smaller values and requires a calibration as function
of frequency. An earlier derived correction function which was applied to the sample temperature-controlled power compensation
calorimeter enables an empirical correction down to modulation periods of about 20 s. The correction function is determined
by analysis of the higher harmonics of the Fourier transform from a single measurement of sufficient long modulation period.
The correction function reveals that the time constant of the instrument is about 5 s rad−1 when a standard aluminum pan is used. The influence of pan type and sample mass on the time constant is determined, the correction
for the asymmetry of the system is described, and the effect of smoothing of the modulated heat flow rate data is discussed.