SALT PRODUCTION YEAR ESTIMATION METHOD

摘要

The present invention relates to a method for estimating a production year of sun-dried salt by measuring a concentration of kalium-40 (K-40). The purpose of the present invention is to easily estimate the production year of the sun-dried salt by detecting an amount of remaining K-40 using a gamma nuclide detecting device based on properties whose insoluble elements gets out at a constant rate when sun-dried salt are left unattended for a long time. To achieve this, the present invention is capable of estimating the production year of corresponding sun-dried salt based on the measured concentration of K-40 contained in the sun-dried salt or bittern melt and which gets out from the corresponding sun-dried salt while measuring the concentration of the K-40 which is a radionuclide analyzing device. If the concentration of the K-40 measured by the radionuclide analyzing device is within a range of 130-220 Bq/kg, the production year of the corresponding sun-dried salt is estimated as one or two years ago. If the concentration of the K-40 measured by the radionuclide analyzing device is 130 Bq/kg or less, the production of the corresponding sun-dried salt is estimated as three or more years ago.