Fluke Biomedical 660-6 - Manual (Page 5)

Introduction
Product Description
1
1-1
Section 1
Introduction
1.1 Product Description
CT Probes, Models 660-6, 500-100, and 6000-100 are designed to be used with Phantoms, Models 660-
7 and 660-8, to measure exposure produced by Computed Tomography (CT) Scanners.
The probes (Figure 1-1) consist of a pencil type ionization chamber with a sensitive length of 10.0 cm.
The Model 660-6 probe chamber is connected, via 0.9 m (3 ft.) of low noise flexible cable, to a signal
digitizing pre-amplifier. It is designed to be readout on a Model 660 Digital Exposure Meter. The Model
500-100 probe chamber is connected to 0.9 m (3 ft.) of low noise flexible cable terminated with a male
BNC size triaxial connector. It is designed to be readout on a quality electrometer. Model 600-100 (not-
shown) is similar to the Model 500-100, but designed for the NERO™
The phantoms (Figure 1-2) are designed in accordance with the definition in the FDA Center for Devices
and Radiological Health, performance standard 1020.33 Computed Tomography (CT) equipment, “NCT
Dosimetry Phantom”. Model 660-7 is a body phantom; Model 660-8 is a head phantom.
1.2 Specifications
1.2.1 CT Probes
Detector Type Vented air ionization chamber
Volume 3.2 cc
Sensitive Length 10.0 cm
Chamber Material: Clear Acrylic
Inside Diameter: 6.4 mm
Wall Thickness: 54 mg/cm 2
Electrode Material: Aluminum
Diameter: 0.64 mm
Sensitivity 10 R cm/nC (nominal)
Factory Calibration 100 KVCP, 5.5 mm Al hvl
Energy Response +5%, 1 mm Al to 10 mm Al hvl (see Figure 1-3)
Uniformity (along axis): + 3% over central 90% of active
length (see Figure 1-4)
Beam Orientation Normal to chamber axis
Phantom Adapter Outside Diameter: 1.27 ± 0.04 cm (0.50 ± 0.015 in)
Model 66O-6
(with Model 660
Readout) Maximum Display: 999 R cm/min, 99.9 R cm
Maximum Resolution: 0.01 R cm/min, 0.001 R cm