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.
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.
The following table lists 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 ALARA 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 mrem|
PLEASE NOTE: Wearing your dosimeter(s) in accordance with the guidelines given above is required in order to obtain an accurate assessment of your radiation.