A method for radiation dosage measurement includes: (1) exposing a plurality of single-poly floating gate sensor cells to radiation; (2) measuring threshold voltage differences between logical pairs of the exposed sensor cells using differential read operations, wherein the sensor cells of each logical pair are separated by a distance large enough that radiation impinging on one of the sensor cells does not influence the other sensor cell; (3) determining whether each logical pair of exposed sensor cells is influenced by exposure to the radiation in response to the corresponding measured threshold voltage difference; and (4) determining a dosage of the radiation in response to the number of logical pairs of the exposed sensor cells determined to be influenced by exposure to the radiation. A non-radiation influenced threshold voltage shift may be measured and used in determining whether each logical pair of exposed sensor cells is influenced by radiation exposure.