LB 790 10-Channel α-β Low-Level Counter with PC-Software AMS

The 10-Channel Low-Level Counter – LB 790 allows simultaneous and separate measurements of low activities for alpha and beta radiation emitting radionuclides with a detection limit of approx. 12 mBq for Alpha (Am-241) and approx. 22 mBq for Beta (Sr-90) (according to ISO 11929; 1 h measuring time)1).




Detection limit is calculated regardless of spillover and calibration uncertainty.

Measuring times (sample = background), 5% error probability, background value of 0.1 cpm for Alpha and 1 cpm for Beta.

For Am-241 an efficiency of 34% and for Sr-90 an efficiency of 50% is used.



  • Simultaneous α and β measurement (10-fold sample drawer for planchets up to Ø 60 mm)
  • Guard counter directly above measuring counters to suppress cosmic ray (anticoincidence)
  • 10 cm lead shielding in all directions for optimal low background performance
  • Modular sample detector construction (2 detectors per module)
  • Easy servicing concerning maintenance and repair
  • Detectors and sample drawer are one unit
  • Preamplifiers integrated in the detector
  • New PC Windows-Program AMS (Activity-Measuring-System for Data Acquisition)