Iodine-125 Calibration Tubes
Iodine-125 (I-125) calibration tube sources are used in clinical laboratories, and research settings for gamma counter calibration, quality control, and counter efficiency monitoring. Sealed solid state sources emit low-energy gamma photons in the 27–35 keV range, making them ideal for normalization and verification of gamma counters designed for low-energy detection, including radioimmunoassay (RIA) systems.
Matching Set
A set of I-125 tubes consists of multiple sealed sources with closely matched activity to minimize variability during calibration and verification procedures. Matched sets are typically specified within a tight tolerance of ±1.5% or better. A Daily DPM log with expected decay-corrected values is provided for ongoing verification of counter efficiency.
Design and Construction
I-125 calibration tubes are sealed to prevent contamination and ensure stability over their usable life. Tubes are manufactured to standard dimensions for compatibility with gamma counters and well counter systems. Tube size is 12 x 75 mm.
I-125 Calibration Tubes for
Gamma Counter Calibration: Establishes counting efficiency for low-energy isotopes
RIA and Ligand Binding Assays: Ensures consistency and reproducibility
Quality Control: Routine monitoring of instrument performance
Instrument Validation: Verification during installation and service
Cross-Calibration: Alignment between counters and laboratory systems
Handling and Safety
Although I-125 sources are sealed and low activity, proper handling and storage procedures should be followed in accordance with radiation safety guidelines and local regulations. Due to the lower photon energy, attention should be given to contamination control and consistent geometry during counting. Regular verification of activity is recommended.