Radiation and Stack Air Monitor


The MISTRAL XM air activation monitoring system is designed to sample and monitor the gamma activity concentration resulting from air activation, in Marinelli geometry.

The MISTRAL XM Rooms is designed for free air monitoring (up to 8 sampling points), whereas the MISTRAL XM Stack is used to monitor the air expelled from a chimney or a stack.


In both cases, MISTRAL XM (where “X” stands for the number of sampling points) is composed of two main parts:

  • Acquisition and processing unit: APU
  • Sampling and detection unit: SDU-XM

The APU consists in a cabinet with a 19” rack, and includes the PC, the monitor, and the electronics components.

The SDU-XM consists in a NaI(Tl) detector coupled to a MCA, a lead shielding, a pump to sample the air, a flow switch to control the pump functioning, and an array of electro-valves for automatic air sampling. The system also manages the expulsion of the monitored air.

As an accessory of the Stack version, a flow rate meter (STACK-DFM) can be installed into the stack, allowing the system to calculate the specific activity of the expelled air volume.

The software installed on the PC displays in real time the measurement, controls the system status, and allows to set the operative parameters, such as the alarm thresholds. The user can define specific regions of interest (ROIs) and thus determine the specific activity (Bq/g) of the sampled air.

Additional Info

Main features:

  • Extremely high sensitivity
  • Rooms and stack monitoring
  • Fully configurable work cycle
  • Lead shield for 3 liters Marinelli geometry
  • NaI(Tl) detector coupled to MCA
  • Typical MDA: <1 Bq/l of F-18 for 300 s measurements>
  • Pump to sample and expel the air
  • Interception electrovalves for the multiplexed automatic sampling of up to 8 rooms
  • Acquisition and processing software with display of the energy spectra
  • Relays for remote devices control