Gamma Sources

The products shown on these pages are representative sources used for common applications.

If you cannot find the product with your specifications, please contact us using the corresponding email contact on this website. In most cases we will be able provide you with a solution meeting your requirements.

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Please select one of the types listed below:


General information


These gamma reference sources are designed for calibrating and checking gamma-ray spectrometers, gamma counters and electron spectrometers. Typical applications in research, environmental measurements and nuclear medicine include:

1) Calibrating high resolution gamma-ray spectrometers

  • Single radionuclides
  • Sets of sources
  • Mixed radionuclide point sources with low self-absorption

2) Calibrating NaI spectrometers

  • Single radionuclides
  • Mixed radionuclide point source

3) Calibrating NaI counters

  • Tube type sources

The advantages of the sources described are:

  • Sealed sources -robust design for cost effective, long, useful life
  • Easy to mount in jigs for reproducible measurement conditions
  • Choice of capsule dimensions and source activities
  • Minimal self-absorption and small active volume -accurate calibrations
  • Traceable to national standards laboratories including NIST, NPL, PTB, LNHB


The maximum deviation of the delivered activity from the nominal values stated is ±30%, unless stated otherwise.


The reported uncertainty is based on a standard uncertainty multiplied by a coverage factor k=2, providing a level of confidence of approximately 95%.


The sources are traceable to standards held by national laboratories such as the Physikalisch-Technische Bundesanstalt (Germany), the National Physical Laboratory (UK), the National Institute of Standards and Technology (USA), the Laboratoire Primaire des Rayonnements Ionisants (France), and many other laboratories world-wide. Further details are given in section 9.1.


Each source is supplied with a certificate of calibration which states:

  • Activity of radionuclide
  • Uncertainty
  • Reference time and date
  • Activity of any gamma-ray emitting impurities detected, expressed as a percentage of the activity of the main
  • Radionuclide at the reference time
  • Serial number
  • ISO classification
  • Results and date of leakage test

Quality assurance

The sources are calibrated at Eckert & Ziegler Nuclitec`s DAkkS accredited measurement laboratory at Eckert& Ziegler Nuclitec in Germany. The facility operates a quality management systems which has been independently audited and approved to ISO9001:2008.

ISO classification

The International Organization for Standardization has published a classification of sealed sources based on safety requirements of typical usage. The source types have been tested to ISO2919 which is equivalent to ANSI N542-1977. The ISO classification is given for each source type in the following pages.

Useful working life

The useful working life of the sources is usually limited by the half life of the radionuclide. In addition, regular improvements in source design and measurement mean that it is good working practice to renew the sources every 10 years.


Sources are normally delivered within 6 weeks from receipt of order.

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USA / North and South America / Australia / China & Far East Asia


Eckert & Ziegler
Analytics, Inc.
1380 Seaboard Industrial Blvd.
Atlanta, GA 30318

Phone: +1 404 352 8677
Fax:     +1 404 352 2837

Europe / Africa / Middle East Asia / Japan

Eckert & Ziegler

Nuclitec GmbH
Gieselweg 1
38110 Braunschweig

Phone: +49 5307 932 0
Fax:     +49 5307 932 272



Eckert & Ziegler Isotope Products France
12 avenue des Tropiques
Hightec Sud - bâtiment B
91955 Courtaboeuf cedex
Phone: +33 1 64 86 22 22
Fax:     +33 1 69 86 10 65