Radon/Thoron Decay Products
- Radon & Thoron
- Radon/Thoron Decay Products
- Radioactive aerosols, air sampling
- Radioactive contamination, source search
DOSEman PRO: Radon progeny dosimeter
The<em?>DOSEman PRO was developed as a personal dosimeter within a project of the Federal Office for Radiation Protection for the precise determination of exposure to short-lived radon decay products. It is also suitable for continuously measuring the time course of radon decay product concentrations. Combined with a radon monitor (e.g., RTM 1688-2 ), the user has a cost-effective method for determining the equilibrium factor.
The dimensions and weight of the radon decay product dosimeter allow the DOSEman PRO to be worn on the body without restricting freedom of movement. With a fully charged battery, the device can operate for more than 40 hours. Thanks to the optimized measuring head, no maintenance is required other than a monthly filter change (in continuous operation and in air with normal dust levels).
The display of the DOSEman PRO radon daughter product dosimeter can be switched between the integral values, “Potential Alpha Energy Exposure” (PAEE), and equivalent dose, as well as the current concentration values, PAEC, and “Equilibrium Equivalent Radon Concentration” (EEC). The equivalent dose is calculated using a selectable coefficient. If a defined dose limit is exceeded, an audible alarm is triggered.
RPM 2200: Radon/Thoron progeny monitor
With the RPM 2200 we offer a high-quality and modern radon decay product monitor.
The newly developed measuring head enables quick, tool-free filter replacement. A processor-controlled rotary vane pump ensures a constant airflow through the filter. To ensure immediate detection of a worn or broken filter, a sensor continuously measures the pressure drop across the filter.
We use a light-protected silicon detector with a sensitive area of 400 mm² . In combination with the fine-pored membrane filter, optimal spectroscopic resolution is achieved for the separation of the individual radon decay products.
The analysis is performed continuously, meaning that the separation of the decay products and the determination of the activity of the collected decay products take place simultaneously. Equilibrium equivalent concentration (EEC) and potential alpha energy concentration (PAEC) are output for radon and thoron decay products, respectively.
Due to the long half-life of the thoron progeny, Po-212, the filter activity cannot be used directly to determine the thoron progeny concentration (response time of approximately 40 hours). To achieve meaningful time resolution, e.g., for the representation of a daily cycle, the Po-212 activity curve is differentiated.
The current measured values are displayed on a large touchscreen. All measurement data, including a complete alpha spectrum for each measurement point, is stored on a two-gigabyte memory card and can be accessed from a PC via the USB interface. Cellular modems or ZigBee adapters can be used for data transmission and device control.
EQF 3200 : Radon/Thoron gas and progeny measurement system
The EQF 3200 is the ideal monitor for a comprehensive assessment of the radon situation regarding radon availability and expected dose. The device determines the gas and decay product concentrations for radon and thoron, respectively, as a basis for calculating the equilibrium factor.
High-quality semiconductor radiation detectors are used in both the radon measurement chamber and the decay product measuring head. These enable perfect separation of the individual radon decay products using alpha spectroscopy.
The newly developed measuring head enables quick and tool-free filter replacement. Fine-pored membrane filters with fabric reinforcement are used. A processor-controlled rotary vane pump ensures a constant air flow through the filter. To ensure immediate detection of a depleted or perforated filter, a sensor continuously measures the pressure drop across the filter.
The measurement chamber, which operates according to the principle of high-voltage deposition, offers excellent sensitivity while maintaining a small volume, which is a decisive advantage, especially for thoron measurements and small sample volumes. The long-term contamination caused by the growing polonium-210 background, which is common with other measurement principles, is completely eliminated.
There is no cross-sensitivity to ambient radiation. The chamber is insensitive to fluctuations in humidity. The desiccant cartridge, which is normally used in devices using this measurement method, is not required here.
Since quality assurance is a central element of every radiation measurement, the EQF 3200 stores a complete alpha spectrum for each measured value, which can be used to determine the proper functioning of the device at any time.
The current measured values are displayed on a large touchscreen. All measurement data is stored on a 2 GB memory card and can be accessed from a PC via the USB port. Mobile modems or ZigBee adapters (Wi-Fi) can be used for data transmission and device control.
The EQF 3200 can optionally be equipped with a NaI detector for determining the gamma dose rate. Additional internal inputs and outputs are available for connecting customer-specific sensors and actuators. Some examples are listed in the data sheet.
The device is delivered with a factory calibration certificate. Calibration for radon (RN-222) is performed according to the specifications of DIN EN ISO 17025.
EQF 3220 : Size-specific Rn/Tn gas & progeny measurement system
The EQF 3220 is our flagship portable radon and decay product monitor. It contains all the components necessary for a scientific and comprehensive assessment of a local radon situation. In addition to radon and thoron gas, the concentrations of radon/thoron decay products are determined depending on the particle size of the carrier aerosol. In addition to the free (< 5 nm) and deposited (> 100 nm) fractions, the cluster component in the range of approximately 20 to 100 nm is also measured. This is primarily present in the air during ongoing combustion processes.
The small aerosol measuring head can be removed from the device and positioned freely in the room as needed. The fine-pored, fabric-reinforced membrane filter for measuring the deposited fraction can be changed quickly and without tools. A processor-controlled rotary vane pump ensures a constant airflow through the filter. A stainless steel grid is used to separate the free byproducts, which can be freely exposed to the drawn-in air. Extensive tests have demonstrated excellent reproducibility of the measured values.
Only high-quality semiconductor radiation detectors are used in both the radon measurement chamber and the aerosol measurement head. These enable perfect separation of the individual radon decay products using alpha spectroscopy.
The radon measurement chamber, which operates according to the principle of high-voltage separation, offers excellent sensitivity while maintaining a small volume, which is a decisive advantage, especially for thoron measurements and small sample volumes. The long-term contamination caused by the growing polonium-210 background, which is common with other measurement principles, is completely eliminated. There is no cross-sensitivity to ambient radiation. The chamber is insensitive to fluctuations in humidity. The desiccant cartridge, which is normally used in devices using this measurement method, is omitted here.
Quality assurance is a central element of any radiation measurement. Therefore, the EQF 3220 stores a complete alpha spectrum for each measured value, which allows immediate confirmation of the device’s proper functioning at any time during the measurement.
