Frisker with Dose Equivalent Filter - Model 26-1 DOSE
Introduction

The Model 26-1 uses a time-test GM detector in an ergonomically designed, ruggedly-constructed, and water-resistant housing using cable-less design. These features combine with other user-friendly functions such as large LED display, automatic backlighting, and 3-button operation to make surveying personnel and objects into a neat operation. The Model 26-1 DOSE is a Model 26-1 that includes a removable energy compensation filter that flattens the energy response to facillitate measuring Ambient Equivalent Dose (Sieverts). See graph below, and attached Report on the Downloads tab for further performance details. 
 
As many know, the venerable GM pancake has a significant over-response at lower energies between approximately 20 to 160 keV (see red line on graph below). Any dose measurements taken with an unfiltered GM pancake detector would thus have unacceptable errors at these lower energies. This  filter developed by Ludlum flattens the response to within  ± 20% referenced to 137Cs (662 keV) over an energy range of 20 keV to 1.2 MeV.
 
The Model L-2002-1050 Ambient Dose Equivalent Filter simply snaps on across the face of the Model 26-1 whenever these types of measurements are desired. The filters are then easily removed to allow the operator to continue with measuring contamination.
 
The Model 26 series may also be ordered with a standard 1/8 inch plug, mono headphone jack to better monitor the instrument's audible output in noisy environments. Part Number 4498-538. See more under the Options tab.

Energy Graph

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 44-9 DOSE: Model 44-9 detector with snap-on Dose Filter (PN 47-3789)
 
Energy Compensation Filter Kits
Ambient Dose Equivalent Filter Kit: includes snap-on filter (PN 2002-1050)