Wearing a dosimeter is an important part of radiation safety for workers who are exposed to high-energy gamma or beta radiation. It is essential to understand when and how to wear a dosimeter, as well as the regulations and guidelines that govern their use. This article provides a comprehensive guide to dosimetry, including when dosimeters should be worn, the types of dosimeters available, how to put them on, when to return them, and what the results mean. At UTHealth, we appreciate the opportunity to provide dental care for your entire family.
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When should dosimeters be worn?Radiation workers who operate x-ray machines, fluoroscopy units, certain unsealed and sealed radioisotopes, or who are exposed to other sources of high-energy gamma or beta radiation generally must use one or more dosimeters. Wear your badge every day while you work and place it in a radiation-free area after work hours.
Do not remove the badge from your workplace. Place the badge on the neck or chest area, facing the radiation source.
What types of dosimeters are there?UTHealth uses two badges for most employees: Luxel by Landauer (aluminum oxide dosimeter) and TLD (thermoluminescent dosimeter). The Luxel badge measures the total body dose of X-ray, gamma radiation and beta radiation.
The TLD measures the dose in the extremities (fingers, hands, etc.). The TLD chip is housed in a plastic ring for carrying in the dominant hand.
How do I put on my ring dosimeter?The ring badge should be worn on a finger with the label (white plate) facing the radiation source, i.e., towards the palm of the hand where the greatest exposure occurs. Protect the ring badge from contamination by wearing it inside a glove.
Check the badge as part of your routine survey for personal contamination. Ring badges are available in small, medium and large sizes; if your ring doesn't fit you, let us know. When you're not wearing the ring badge, store it in a place protected from radiation and heat.
How do I put on my whole body dosimeter?Radioactive workers who are issued full-body badges should wear them on the neck, mid-torso, or waist with the tag facing out. The intention is to wear the badge in the area most likely to receive exposure.
When you're not wearing the full body badge, store it in a place protected from radiation and heat.
When do I return my dosimeter?Dosimeters are issued for two categories: monthly and quarterly. The dates of use are printed on the front of the badge, below your name, as a reminder of when to wear them. Once the wearing period ends, remove the badge, keep the gray backing and return the badge to Radiation Safety. If you expect dosimeters and don't receive them before the third business day of the month, call the Radiation Safety Program for more information. At the end of the month or quarter, dosimeters should be returned to Radiation Safety as soon as possible to speed up processing.
All badges are processed in accordance with the accrediting agency of the National Laboratory Accreditation Program.
What do the dosimeter results mean?The main occupational dose limit for the whole body is 5000 millirems per year, equivalent effective dose. The dose limit on extremities (hands, fingers etc.) is 15000 millirems per year. The national average annual exposure to background radiation (non-occupational) is 625 mrem (NCRP 160).
How can I finish a dosimeter?When a Radiation worker drops out of college or changes places of work, notify Radiation Safety to update records. The shipping containers received by unit coordinators that contain monthly or quarterly radiation dosimeters are designed to be reused to return them to Radiation Safety. Fetal dosimeters have a monthly frequency and should be worn at waist level under any lead garment.
Dosimeters are required to be issued if a person is likely to receive more than 10 percent of maximum allowable dose. At the end of usage period replacement dosimeters will be distributed through designated badge coordinator. A) Licensee may not allow any person to act as radiographer or assistant radiographer unless at all times during radiographic operations each person carries on trunk of body direct-reading dosimeter an operational alarm frequency meter and personnel dosimeter. C) Pocket dosimeters or electronic personal dosimeters should be reviewed for periods not exceeding 12 months to determine correct response to radiation and records must be kept in accordance with § 34 83. Film plates should be replaced at least once a month and all other personnel dosimeters that require replacement should be replaced at least quarterly. D) If person's pocket camera is found out of scale....