Ionizing Radiation Metrology

IRML is one of the departments of Metrology of Heat and Ionizing Radiation Division at the National Institute for Standards. It is assigned to calibrate ionizing radiation measuring instruments on the national level according to law establishing the institute and the labor law of radioactive sources. IRML is a member of the International Atomic Energy Agency / the World Health Organization (IAEA/WHO) network of Secondary Standard Dosimetry Laboratories (SSDLs) since 1977, for high dosimetric accuracy particularly in external beam radiation therapy and other fields.

The department possess secondary standard systems used for measuring ionizing radiation with high accuracy in medical (diagnostic and therapeutic), industrial and environmental fields which are traceable to SI units in BIPM-Paris.


Holding, dissemination and developing of national standards for radiation dosimetry units.


  • Calibration of radiation measuring instruments.
  • Provide traceability to national standards of radiation measurements to users in Egypt.
  • Development of primary and secondary standard dosimetry system.

National Activities

  • Development of calibration methods for different levels of radiation doses.
  • TLD personal dosimetry and radiation workers.
  • Performing calibrations for radiation measuring equipments used in different applications.
  • Low level background activity measurements.
  • Providing technical consultation and advice upon request to industry, medicine and other sectors.
  • Researches in the fields of producing and testing new radiation dosimeters and calibrations.
  • Participation in the national and international conferences.
  • Organizing special training courses in the fields of :
  1. Radiation dosimetry.
  2. Calibration techniques.
  3. Radiation protection.
  4. Types of ionizing radiations and its interaction with matter.

International Activities

Participation in annual international audits organized by SSDL network at the following fields:

  • TLD audit in radiotherapy level
  • TLD audit in protection level
  • Transfer chamber therapy level.
  • Recent participation at the intercomparison organized by regional metrology organizations (RMOs) for the:
  • APMP high dose CO-60
  • APMP. RI (I)- K 1.1
  • APMP. RI (I)- K 4

Instruments and Equipments

1-Radioactive Sources:

 γ-ray sources: (Cobalt-60) with different activities 5 mCi, 5 Ci and 550 Ci and Cs-137 with activity 500 Ci used for :

  • Calibration of different gamma ray detectors.
  • Calibration of survey meters.
  • Calibration of personal dosimeters.
  • Samples irradiation.
  • Neutron sources: Am-Be with activities;1 Ci, 5 Ci and Cf-252 with 0.00168 activity Ci used for:
  • Calibration of neutron survey meters.
  • Calibration of different types neutron ionization chambers.
  • Samples irradiation.

Radon and alpha particle sources used for:

  • Measurement of radon concentration.
  • Calibration of radon detectors.
  • Calibration of radon gas sources.

2- Equipment:

Reference standard dosimetric systems including different electrometers such as NPL, Farmer & Unidos and different ionization chambers for different radiation ranges and applications calibrations.

  • Neutron monitors and neutron ionization chambers.
  • TLD systems (type 4500 and 6600) for personal protection level dosimetry.

Electron Spin Resonance system used for :

  • Measurement of high doses radiation.
  • Dose calibration for high activity gamma ray sources (sterilization and food irradiation doses).
  • Measuring the number of free radicals in organic and inorganic samples.

Hyper pure Germanium and sodium iodide with multi-channels analyzer systems used for:

  • Calibrations of hyper pure germanium and sodium iodide detectors.
  • Efficiency determination for different types of hyper pure germanium and sodium iodide detectors.
  • Radioactive leakage measurements from different sources.
  • Specific activity measurements for powder and liquid samples.
  • X-ray irradiation machine for calibration of ion chambers in different beam quality and samples irradiation.
  • Environmental radon gas concentration measuring system.
  • Image analyzer system for nuclear track counting in solid state detectors and imaging different samples.