• Measurement of the 3H activity concentration in room air and exhaust air
  • Mixing and pumping system (internally installed)
  • Flow meter tube (internally installed)
  • Optimization for maximum 3H sensitivity or low spillover


  • Low influence due to increased background radiation levels or other gaseous nuclides
  • Detector with thermostatically controlled heater (optional)
  • Compensation of the underground radiation level or other gaseous nuclides
  • Direct and specific measurement


Additional Features

  • Two different counting gases selectable: methane (CH4), argon-methane (P10)
  • Two different data acquisition systems selectable: LB 9000 data logger, LB 5340 data logger
  • Pump and detector unit incl. operating electronics

Product Overview

LB 110


The accuracy of the measurement is dependent on the constancy of the mixing ratio of air and counting gas. Due to that the LB 110 ensures a good and reliable gas-air control. Measuring air and counting gas flow are measured separately and kept at a constant level via a control circuit. The current gas and air flow rate is measured using an electronically controlled flow-through meter which operates according to the principle of thermal mass measurement.

An essential benefit of this principle is that the measurement is largely independent of pressure and temperature. Compared to volumetric principles, neither pressure nor temperature has to be measured in addition. The electronics integrated into the air and gas module is used to control and evaluate the signals modified by the flow-through controller. Gas and air supply are measured separately and kept on a constant level by one control circuit each.

Read More

Technical Data

Mechanical Data 
Dimensions (L x W x H)500 x 420 x 335 mm3
Active volume1,3 l
Weightapprox. 20 kg
Technical Data


Measuring range500 Bq/m 3 - 20 MBq/m3
Background in 3H channel< 3 cps
Ambient Conditions 
Operating temperature0°C to 50°C
Relative humidity0 to 90%, no condensation
Gas- and Air Connections 
GasØ 7 mm
Measuring airØ 7 mm
Outlet for gas-air mixtureØ 7 mm