Evaluation of calibration factors of digital survey meters in a secondary standard dosimetry laboratory.

This article focuses on the calibration of digital radiological survey meters at the Ghana Secondary Standard Dosimetry Laboratory (SSDL) to ensure traceability to the International System of Units (SI) and improve dose standardization. Seventy-one survey meters from various industries were calibrated using a ^137Cs source and a PTW spherical ionisation chamber with a PTW UNIDOS Electrometer, yielding calibration factors (CFs) ranging from 0.59 to 1.98; 64% of the meters had CF deviations within ±20%, while 36% exceeded this threshold. The study emphasizes the importance of periodic recalibration to correct measurement errors and advises end users to incorporate their own uncertainty assessments alongside those provided by the SSDL. The Ghana SSDL, established under the International Atomic Energy Agency (IAEA) and World Health Organization (WHO) network, provides calibration services traceable to primary standards in Austria and Germany, supporting radiation protection across multiple sectors.