Extremity dosemeter 02-10.indd

The Personal Dosimetry Service of the Health Protection Agency provides extremity dosimetry based on alternative forms of themoluminescence dosemeter (TLD): the fi nger stall and the ring. The dosemeters are designed to measure doses from X-, beta and gamma radiations to the skin of the extremities (ie the hands and feet) in terms of the radiation quantity H (0.07), the dose equivalent at a depth of 0.07 mm, as required by the Health and Safety Executive (HSE). The dosemeters are issued as part of the HPA TLD dosimetry service, which is approved by the HSE under Regulation 35 of the Ionising Radiations Regulations 1999. The performance of the two types is very similar, with the fi nger stall being preferred where low energy radiations are used. The dosemeter elements are produced by Harshaw TLDTM, part of the Thermo Electron Corporation, and are individually Finger stalls are available in two sizes, radiation until they are heated (in this is released as light. The amount of light strip of KaptonTM foil containing a thin released is proportional to the radiation layer of sensitive lithium fl uoride powder at one end. The sensitive area is covered very thin and which allows very low energy into an automated TLD reader which identifi es the dosemeter, heats it to the adjustable format which will accommodate fi nger diameters up to 29 mm. The dosemeter element is of the Harshaw sensitive elements facing the predominant direction of the radiation – in the case of containing a thin layer of sensitive lithium the fi nger stall, the aluminised side should fl uoride powder. The element is covered face the source, and, in the case of the by a fl attened plastic dome with a thin fi nger ring, the domed dosemeter housing The extremity dosemeter service is just one of the approved dosimetry services offered by the Health Protection Agency and can be linked to our dose record keeping service via an automated system. The processing laboratory is based at our centre at Chilton. For further information or to place an order please contact us on the numbers below.
Centre for Radiation, Chemical and Environmental Hazards Technical Specifi cation
Measurement uncertainties
Material
The extremity dosemeters are subject to measurement Dose range
uncertainties which comply with the recommendations given in Change interval
Periods of 1, 2 or 3 months also available Radiation Protection 160: Technical Recommendations for Monitoring Energy dependence of response
Individuals Occupationally Exposed to External Radiation.
Finger stall –25% to +15% for photon radiations from 16 keV to 1250 keV
and overall bias are typically 10% (allowed values: 15% and 20% Special Features
–10% to +20% for photon radiations from 20 keV to 1250 keV exceptionally low beta energy detection threshold of 224 keV (E ).
The dosemeters may be worn in all normally encountered environments. In ultraviolet light (including sunlight) should be avoided.
Angle dependence of response
Styles to suit allThe extremity dosemeter is available in Finger stall
Within ±10% up to 90° for photon radiations and ±20% up to 60° for beta radiations a wide range of styles to suit everyone. The fi nger stall is available in small and Within ±25% up to 60° for photon radiations and ±45% up to

Source: http://www.medicalconsult.pt/dosimetrosExt.pdf