Radiation Monitoring

A radiation monitoring badge or Thermoluminescent Dosimeter (TLD) is the most common method of tracking how much radiation a worker is exposed to during a certain monitoring period. In general, badges/TLDs are exchanged on a quarterly basis (every 3 months). The dosimetry program at the University of Guelph is managed by Environmental Health & Safety and the Radiation Safety Officer (RSO).

Do I require a TLD?

Many of the sources utilized at the University require some level of radiation monitoring, you are required to apply for a TLD badge if you’re working with:

  • Gamma sources
  • High-energy beta emitters (e.g., P-32, Sr-89, Y-90, etc.)
  • Unshielded/open X-ray devices

How do I apply for a TLD badge?

Once you’ve completed the relevant and mandatory safety training (radiation safety and/or X-ray safety) you may apply for a TLD Badge:

  • Download and complete the Personal Dosimeter Badge Application Form
  • Submit the form to the EHS main office (Alexander Hall 162) or through fax (519-824-0362)
  • A personal TLD badge will be issued for the current monitoring period and you may begin work

Keeping Track of TLD Badges

Most personnel working with radiation will have permanent TLD badges and thus must be exchanged every three (3) months while actively working with radiation sources.

Please note the following dates for returning and ordering new badges:

  • January – March: due by November 8th
  • April – June: due by February 14th July – September: due by May 15th
  • October – December: due by August 14th

For more information on dosimetry please consult the Radiation Safety Manual or contact the RSO at: radsafe@uoguelph.ca / EHS Service Associate x53282