LB 2050 Clearance Monitor

The Clearance Monitor LB 2050 has been specially designed for clearance measurements which are required for the disposal of radioactive waste with negligible radioactivity in accordance with the German Radiation Protection Ordinance of 2001.

For clearance as non-radioactive substances, nuclidespecific limit values (total activity and specific activity) must not be exceeded. This requires measurement of the sample activity (Bq/g) and the surface contamination (Bq/cm²). The Clearance Monitor LB 2050 is designed for the measurement of the massspecific activity and the surface contamination.

Cleared objects can be treated and disposed as nonradioactive objects. However, the appropriate regulations have to be observed if these substances are toxic. Objects whose activity exceeds the permissible limit values are treated as radioactive substances and have to be handled accordingly.

The Clearance Monitor LB 2050 indicates the storage time for the respective nuclide until the radioactivity of waste has decayed so much that the values fall below the legal clearance levels. All clearance measurements are automatically documented in accordance with statutory and regulatory requirements.


  • 6 large area Xenon filled proportional counter tubes
  • Detectors arranged in 4-Pi geometry
  • Approx. 150 liter volume
  • 5 mm all-around lead shielding (optional 7 mm)
  • Easy and ergonomic loading of waste containers
  • Integrated load cell
  • 2 compensation detectors  in case of fluctuating background (optional)
  • Operation by means of a standard PC with a special software
  • Easy handling even for un-trained users (semi-automatic or automatic mode)
  • Administrative tools for a radioactive waste depot

The nuclide-specific clearance levels of the total activity and specific activity which have been defined new in Directive 96/29/ Euratom apply to all radionuclides that are typically used in nuclear medicine.

The Clearance Monitor LB 2050 is based on BERTHOLD’S proportional counter tube technique which has been tried and tested for several decades and which is ideally suited for the measurement of these isotopes.

In nuclear medicine, waste is very often collected and stored in plastic containers holding 30 to 60 liters. A 4-Pi arrangement of the detectors is required to be able to carry out representative measurements of these waste containers. The standard version of the Clearance Monitor LB 2050 is therefore using six large-area proportional counter tubes with a total of 10 measuring channels, covering a volume of about 150 liters in 4-Pi. The large-area proportional counter tubes on the side walls are split up into two measuring channels each, so that different waste distributions, especially for radioactive liquids, can be taken into account.

Waste containers can be placed ergonomically and easily into the metering box by means of a door and a base plate mounted on two sliders. The built-in detectors are protected by a grid against mechanical damage. A load cell scale is integrated in the bottom of the container slider; this does not have any adverse effect on the sensitivity
of the bottom detector. Thus, any radioactive liquid may be measured optimally. The integrated loading display shows the container weight in the metering box and sends the data to the PC for further processing.

The measuring station is delivered with a 5 mm thick all-round lead shielding (optionally 7 mm). If strongly varying background radiation is likely to occur at the Clearance Monitor’s setup location, the measuring station may also be provided with
up to two background compensation detectors.

The Monitor is operated by means of a standard PC. Clearance measurements can be carried out by untrained personnel in a semi-automated operation in the Routine measuring mode using pre-defined factors (container type, nuclide, calibration
factors, etc.). 

The Automatic mode supports measurements which do not require operation via PC: loading and unloading of the metering box and operation of the Start/Stop button on the metering box control the measurement procedure.

For radionuclides like 11C, 18F, 57Co, 90Sr, 99mTc, 111In, 125I or 131I in typical waste containers filled with low density waste detection limits below 0.2 Bq/g can be achieved within a few minutes. The monitor also measures simultaneously the surface contamination of the container on all sides.

In addition to the Monitor’s operating functions, the software program offers administrative tools for a radioactive waste depot in accordance with the radiation protection guidelines. 

Technical Data
Measuring ChamberStainless steel, mobile, front door access, base plate on sliders for ergonomic loading
Front PanelSimplified use with status lights and Start/Stop buttons
Clear status indication via red, green, yellow and blue LEDs



β and γ detection 6 Xenon large area proportional counters with integrated HV supplies and preamplifiers

4 x 2000 cm2 detectors sideways

2 x 1000 cm2 detectors top and bottom

Optional max. 2 compensation detectors in case of fluctuating background
Protective gridsTransparency 80 %

5 mm lead (optional 7 mm) covering all sides of the measuring chamber

Loading scaleIntegrated in the container slider (max. 100 kg)


Outer dimensions

577 x 800 x 1100 mm3 (W x D x H) incl. wheels
Innerdimensions477 x 477 x 650 mm3 (W x D x H) or 147.9 liters



approx. 207 kg with 5 mm lead

approx. 240 kg with 7 mm lead

Software functions


User management

user registration (password)

parameter entry

reference sources

calibration routines (special password for calibration)

automatic background measurement

identification container type

selection of nuclide(s)

failure and fault monitoring

clearance measurement

measurement protocol

label printer output

data base

functions for storage, sorting, filtering & release


It is used wherever contamination caused by radioactive waste material is encountered, transmitted or disposed:

  •  Nuclear Medicine
  • Laboratories
  • Research Institues
Format Size
LB 2050 en PDF 105.63 KB
Press & Media
Format Size
LB 2050 en PDF 3.07 MB