Myriam Personal Dosimeter

Dose determination of long-lived  alpha and beta emitters in breathing air

• Measurement principle: continuous deposition of long-lived radioactive aerosols on a membrane filter, pump, semiconductor detector, alpha spectroscopy and beta counting
• Dose determination using ICRP 68 dose coefficients for Pu-239 and Sr-90
• Short response time of  60 seconds
• Secure against manipulations by an access code
• Short battery recharge time
• Data memory for 240 data records
• Optical and acoustic alert functions
• Proven in many years´ use in mines. in the event of reactor accidents and in disaster control
• Optionaly data remote transfer

The personal dosimeter MyRIAM determines the inhalation dose obtained from the exposure to long living Alpha and Beta nuclides (LLRD) in the breathing air. The aerosols will be accumulated on the surface of a membrane filter by an internal pump. The collected activity is analysed by a semiconductor detector with subsequent Alpha spectroscopy and Beta gross counting. The influence of natural occurring Radon daughters is fully compensated

An accurate determination of the obtained dose without any additional equipment is possible by a special filter analysis mode. The small filter paper (17,5 mm diameter) can be archived and used for preservation of evidence.

The lightweight (300g) instrument can be worn on the body without impairment of the mobility. Sampling head, battery and electronics have been integrated into a rugged metal enclosure of the size of a mobile phone. Therefore, no additional cables and hoses are required

Dangerous doses will be detected within 60 Seconds and signalised by an acoustical and an optical alert. The display, equipped with a with bright back-light shows the recent dose values (μSv or mrem) as well as the over all count rates. The internal rechargeable battery allows approx.24 hours of autonomous operation – it takes only one hour to recharge the battery.

No other maintenance is required than the battery recharging and a monthly and easy to perform filter replacement. The internal data logger enables a chronological (local) assignment of the obtained dose contributions.The communication between PC and MyRIAM is realised by a infrared data link.

The software for easy data analysis and archiving is included in delivery.