The University of Iowa

VAMC Dosimeter Guidelines - Personnel Using X-Ray Diffraction Equipment

The purpose of this guide is to establish a uniform protocol for the placement of radiation dosimeters for all individuals using x-ray diffraction units at the University of Iowa. The definitions below list each type of dosimeter along with the area it is to be worn and the significance of each reading.

Contact Laurie Scholl, VA Interim Radiation Safety Officer (158-5733 VA) with any questions or concerns.

Dosimeter Types

U3 - Ring dosimeter 

The U3 ring dosimeter provides a measurement of the extremity radiation dose equivalent received by the lower arm and hand. The U3 dosimeter is required to be worn on a finger of the hand likely to receive the highest radiation exposure. A second ring dosimeter (identified as a "U4) worn on a finger of the opposite hand is optional.

ALARA Limits

PLEASE NOTE: Wearing your dosimeter(s) in accordance with the guidelines given below is required in order to obtain an accurate assessment of your radiation. 

The following tables list the regulatory and external dose limits against which personnel dosimeter results are compared.

State of Iowa Limits

Type of Exposure Annual Limit
Whole Body Deep Dose Equivalent (DDE) which includes: head, trunk, active blood forming organs & gonads  5000 mrem/year total
Whole Body Shallow Dose Equivalent (SDE) which includes: skin 50000 mrem/year total
Lens of Eye Dose Equivalent (LDE)  15000 mrem/year total
Extremities 50000 mrem/year total
Limit for person completing pregnancy declaration  500 mrem/gestation period

 VAMC Limits (Quarterly)

Area of Body ALARA Action Level I ALARA Action Level II
Whole Body Deep Dose Equivalent (DDE) 125-374 mrem > 374 mrem
Whole Body Shallow Dose Equivalent (SDE) 1250-3749 mrem > 3749 mrem
Lens of Eye Dose Equivalent (LDE) 375-1124 mrem > 1124 mrem
Extremities 1250-3749 mrem > 3749 mre\