Radiation Detector - Model 44-9
CE Seal

The GM pancake-type detector in the Model 44-9 is arguably the most popular radiation detector used throughout the world. This detector is sensitive to alpha, beta, and gamma radiation, is enclosed within a rugged metal enclosure, and is conveniently shaped and sized for checking contamination on people and objects.

This detector operates between 850 to 1000 volts, and is compatible with any Ludlum instrument capable of supplying 900 Vdc and an input sensitivity of 30 mV or higher.                         

Similar Models

Model 44-40: uses a lead housing to reduce background
Model 44-9-18: incorporates a gooseneck-type flexible end with an extension handle stretching to 0.9 m (36 in.) length
Flatten the Energy Response
The venerable GM pancake detector has a significant over-response at lower energies that produce false dose readings. To correct this situation, Ludlum offers a simple snap-on filter anytime dose measurements are required.
Note: The Model 2002-1050 Dose Filter is designed to fit the Model 44-9 Series of Radiation Detectors with serial number 97000 and higher. It will not fit the Model 44-9-13 or older units unless modified.
Ludlum Measurements offers an energy compensation filter that flattens the energy response of the Model 26 to facilitate measuring the ambient dose equivalent rate. The filter flattens the response to within ±20% referenced to 137Cs (662 keV) over an energy range of 20 keV to 1.2 MeV for ambient dose equivalent.

Energy Compensation Filter Products

Model 26 Integrated Frisker series
Model 26-1 DOSE: Model 26-1 with snap-on Filter (PN 48-4007)
Model 44-9 GM Detector series
Model 44-9DOSE: Model 44-9 detector with snap-on Filter (PN 47-3789)
Filter Kit Modification for Model 26-1 and Model 44-9 instruments
Ambient Dose Equivalent Filter: kit includes snap-on filter and replacement screen (PN 2002-1050)