The present work mainly aims the calibration of the De Pangher Long Counter, used as secondary standard, for the calibration of neutron monitors with moderators. A standard 5-C Am-Be source, relative to the neutron emission rate, was used as the primary standard by the activation method of a manganese sulphate bath. Due to the cylindrical shape of the standard source, its anisotropy factor was determined. Long-term reproducibility tests were performed and the scattering effects were determined experimentally by the shadow cone method.