Fluke Biomedical 90-12 - Manual (Page 5)

Introduction
Product Description
1
1-1
Section 1
Introduction
1.1 Product Description
The 90-12 is a rugged, lightweight, energy compensated, general purpose Geiger Mueller (GM) tube
based hand held probe, with beta shields. These probes are designed to fulfill a variety of radiation
measurement needs. The adjustable beta shield is a 360-degree shield with a linear movement to permit
discrimination between penetrating and non-penetrating radiation. The two windows expose an angle of
180 degrees total in the most sensitive area of the GM tube. With the shield open the probes measure
beta, x-rays, and gamma rays. With the beta shield closed the probes measure penetrating x-rays and
gamma rays. The GM probes are available with MHV or BNC connectors. A coiled coaxial cable style is
available to connect these probes to a wide variety of Victoreen survey meters. Refer to Figure 1-1 for a
general view.
The energy compensation feature permits accurate exposure rate measurements from background to the
maximum range.
1.2 Specifications
Operating Voltage 900 V
Plateau length 100 V (min)
Plateau Slope 0.1 %/V (max)
Temperature Range -40°F to +167°F (-40°C to +75°C)
Relative Humidity 0-95% non-condensing
Wall Thickness 30 mg/cm 2 (tube)
Wall Material Stainless Steel
Maximum Background 15 CPM
Gamma Sensitivity 700 CPM/mR/hr*
* Calibrated to 137 Cs
Energy Response See curve
Housing ABS plastic
Beta Shield Density 1890 mg/cm 2
Connector MHV
Size 1.38 in
∅ x 6.7 in (l) (3.5 x 17 cm)
Weight 0.58 lb (0.26 kg)