Skobeltsyn Institute of Nuclear Physics
Lomonosov Moscow State University

We study the reliability and validity of the measurements of fluxes of protons and heavy
ions of solar energetic particles, made using different experimental techniques and methods for
describing the data obtained with different model functions of the energy spectra. The results of
measurements of heavy ion fluxes of solar cosmic rays (SCR), made by the method of solid-state track
detectors (HDT) in the experiments "Astro" (April 1981 - the station "Salyut-6") and "Platane-3" (1988
- 1989. - station "Mir") have been analyzed and compared with the experimental results VLET and
CRT, performed on the satellite IMP-8. Particular attention was paid to the analysis of the results
obtained by instruments SIS and ULEIS (ACE spacecraft), and the results of measurements of the
fluxes of helium ions in the unit EPEAD satellite GOES. We discuss the problem of approximation of
experimental data on the fluxes of SCR by various functions of the energy (pulse rate) of the particles.
This approximation is often the basis for the interpretation of measurement results. Numerous biases
inherent in measurements of the particle fluxes of SCR, made by different instruments on the Earth's
satellites (AES) and other space vehicles Analyzes have been identified.