[en] The investigation on Kodak-Pathe LR 115 cellulose nitrate recoil track detectors is described. The background was investigated and new measurements were performed to prove the applicability of the sensitivity calculation for water-moderated fission neutrons. It is shown that such track detectors are capable of measuring the fast neutron flux density, using the suggested evaluation methods, with an error of less than 25% when the neutron spectrum can be estimated. They are therefore usable not only for flux density measurements in beam geometry but also for area and accident dosimetry. (author)