X-ray multimeter performance under calibration laboratory conditions.

Area of Science:

• Medical Physics
• Radiological Dosimetry

Background:

• Accurate dose estimation in mammography and radiology relies on precise beam quantity knowledge.
• X-ray multimeters (XMMs) are widely used for quality assurance (QA) due to their compact, solid-state design and ease of use.

Purpose of the Study:

• To assess the performance of two XMMs in low-energy x-ray calibration beams.
• To evaluate the long-term stability of manufacturer calibrations for XMMs.

Main Methods:

• RTI Piranha and Radcal Accu-Gold+ with AGMS-DM+ sensor were used to measure air-kerma rates and half-value layers.
• Measurements were compared against standard instruments and repeated over 2.5 years to track energy response stability.

Main Results:

• Both XMMs performed within tolerance, with air-kerma rates within 2% of reference values.
• XMMs showed satisfactory stability, though some response drift was observed, particularly in the RTI Piranha.
• Nearly all half-value layer measurements were within acceptable limits.

Conclusions:

• The tested XMMs met their manufacturers' performance specifications.
• Recalibration could improve measurement accuracy for certain beam series.
• Further studies under rigorous clinical conditions are recommended.