Radiation Dosimeter Badge and Personal Dosimetry for X-Ray Staff

What a personal dosimeter is and why it is needed

If you are asking what the piece of equipment used to detect radiation is, the answer depends on the purpose. A survey meter or Geiger-type monitor measures radiation levels in a place, while a personal dosimeter is worn by a person and accumulates the dose they receive. Personal dosimetry supports three goals: demonstrating compliance with dose limits, identifying unusually high exposures and guiding improvements in work practice.

Staff in diagnostic radiology receive low doses most of the time, but fluoroscopy, mobile work and procedures near the beam can raise them. Monitoring lets managers see whether protective measures, such as shielding and aprons, are working.

TLD badge, OSL and electronic dosimeters

A TLD (thermoluminescent dosimeter) badge contains crystals that store energy when exposed to radiation and release it as light when heated in a reader. OSL (optically stimulated luminescence) badges work similarly but are read with light, which allows repeat reads. Both are sent to a dosimetry service at the end of the monitoring period, usually monthly or quarterly.

Electronic personal dosimeters display the dose in real time and can alarm at set thresholds. They are useful in fluoroscopy and interventional work where the operator wants immediate feedback. Finger or ring dosimeters are added when the hands are near the beam. The choice should follow a risk assessment by the radiation protection officer and the requirements of the authorities.

• TLD or OSL badges: passive, read by a dosimetry service
• Electronic dosimeters: real-time display and alarms
• Ring dosimeters: for hand dose in close work
• Dedicated badge for pregnant staff where required by policy

How and where to wear the badge

The badge is normally worn on the trunk between the shoulders and the waist. Under a lead apron, it reflects the dose to protected body areas; in fluoroscopy, a second badge is often worn outside the apron at collar level to estimate the dose to the unprotected head, eyes and thyroid. Follow the arrangement approved by your radiation protection officer.

Rules for correct use are simple: wear the badge only for the person it was issued to, keep it in the same place, do not leave it in a car, a hot room or near the X-ray equipment and return it on time. A control badge kept in a low-background area allows the service to subtract background radiation.

Occupational dose limits and investigation levels

International recommendations from the ICRP set an occupational effective-dose limit of 20 mSv per year averaged over five years, with no more than 50 mSv in any single year, and a lower annual limit for the lens of the eye. A pregnant worker is protected by a stricter limit for the unborn child. National rules in the UAE are set by FANR, so confirm the numerical limits and the monitoring categories that apply to you.

Beyond the legal limit, facilities set investigation levels: if a badge shows a dose above an internal threshold, the radiation protection officer reviews work practice. Typical causes include working without protective equipment, standing too close to the beam, long fluoroscopy times or a badge worn incorrectly. Dose reduction habits are covered in our guide on fluoroscopy dose reduction.

Records, aprons and the wider programme

Keep dose results for every worker, make them available to the person concerned and retain them for the period required by the authorities. Confirm record-keeping expectations with FANR. A personal dosimeter measures what reaches the badge; it does not replace shielding and good practice, so combine it with lead apron testing and care and radiation protection in fluoroscopy.

Dosimetry is also part of the evidence needed for a facility licence; see FANR licensing for X-ray equipment. To plan a compliant X-ray room, including shielding and monitoring arrangements, talk to Beckfinity's team.