LB 2046 Portable α-β-Activity Measuring System

The α-β-Monitor LB 2046 / LB 2046-130 has been designed for general radiation protection applications, such as the measurement of α-, β- and γ-activities in wipe sample or on dusted filters, for the analysis of environmental samples, e.g. waste water after evaporation, and for the detection of activities in small quantities of food samples.



  • Simultaneous alpha and beta measurement
  • Closed measuring chamber with scintillation counter
  • Simple operation with touch sensitive graphic display
  • Interfaces: seriell, parallel, USB, Ethernet (optional)
  • Service functions: Plateau, Background, Calibration, System test
  • Permanent data storage
  • Stored nuclide library



The measuring system offers a very compact and economic measurement solution for applications, where spectroscopy or extremely low level counting systems are not required.

A large-area ZnS(Ag) scintillator with 60 mm diameter (LB 2046) or 130 mm diamter (LB 2046-130) is used as a detector for  α- and β/γ-radiation. It is covered light-tight by an approx. 0.4 mg/cm² large alu-vaporized foil. The sample to be measured is placed on a sample carrier and brought fairly close to the detector. Basically, the sample will be measured in the same position in which the calibration has been performed earlier. The sample carrier of LB 2046 allows maximum planchet heights of 8 mm and 60 mm diameter, also filters with diamters of 60 mm and 100 mm can be measured by means of the filter adapter (optional). LB 2046-130 can be used for measurement of filters with 100 mm and 130 mm diameter.
The detection limit essentially depends on the detector sensitivity, on the background and on the measuring time.

The Alpha-Beta Activity Measuring System is capable of measuring α- and β/γ-radiation at the same time or both types of radiation separately. Some Alphas lose a lot of energy due to the pre-absorption in the air and in the entrance window and, therefore, contribute to a spillover into the Beta channel. This alpha nuclide-dependent spillover can be taken into account by using a correction factor.

The touch sensitive graphic display of the instrument offers an intuitive user interface with simple and fast access to all utility functions. With the background recording routine α- and β- background subtraction is provided and stored for correction of the measured value. The calibration routine permits the calibration of the detector for different nuclides. With the system test a performance check for the instrument can quickly be achieved. An extensive nuclide library is available, which allows storage of the required measurement parameters for each isotope and sample type. In addition a calibration factor, measurement units, counting time, and alarm threshold can be defined providing automatic alarming for high level samples. After each measurement the measured value can be printed out together with the sample ID. Halflife decay correction provides the activity for a specific date requested.


MicroprocessorMotorola MC68340 with 32 bit central processor unit
DisplayGraphical LC display touch panel 320 x 240 pixel
Interfacesserial and parallel port for printer or PC, USB, Ethernet (optional)
LanguagesGerman, English
Access protectionPassword
Power supplyWide range input, 90 - 264 VAC, 47 - 65 Hz
High voltage supply   0-1300 Volt, polarity positive, resolution 12 bit
Protection classIP54
Temperature range- 5 °C to + 40 °C
Relative humidity0 % to 90 % (no condensation)
External dimensions250 mm x 285 mm x 330 mm (WxHxD)
Weightapprox. 15 kg (LB 2046) | approx. 25 kg (LB 2046-130)


  LB 2046LB 2046-130
Detector (type/ø)ZnS(Ag) scintillation counter60 mm ø130 mm Ø
Entrance windowaluminised Hostaphan foil, 0.4 g/cm²
Typical efficiencies




30 %

44 %

11 %

29 %

48 %

 9 %

Typical background



0.001 cps

0.14 cps

0.005 cps

1.13 cps


α- in β-channel (241Am)

β- in α-channel (90Sr)

< 50%

< 2.0 x 10-5

Measuring range



0 - 5 000 cps

0 - 50 000 cps


Order Information and AccessoriesIdent. No.
Optional Filter Cartridge for             LB 2046for filters with diameter 60 mm and 100 mm52969


  • Measurements of wipe samples or dusted filters
  • Analysis of environmental samples, e.g. waste water after evaporation
  • Detection of activities in small quantities of food samples
Format Size
LB 2046 / LB 2046-130 en PDF 583.41 KB