246 MI-42-0001 Rev. 19
CT USER INFORMATION: Dosage Factors and Image Quality
10.3.6 Definitions of the Measurement Bases of the Technique Factors
Tube Voltage The kVp can be measured software assisted during each scan via built-in HV-dividers. The values
have been verified at a prototype test by using additional devices like a hyper-pure Ge-detector and
an electronic penetrameter.
Tube Current The mA have been verified at a prototype test using a mu
ltimeter connected to the center ground
point of the high tension transformer. The tube current can be measured software assisted during
each scan.
Scan Time The scan time is the total exposure time (X-ray on) during a scan. It can be measured software
assisted during each scan and is verified at a prototype test measuring the X-ray on-signal with an
oscilloscope.
10.3.7 60601 Requirements: CT USERS
IEC 60601 IEC 60601-2-44 requires the following information in addition to requirements already met in this
chapter.
Nominal Focal Spot
Value
1.0 x 1.0 mm
Minimum battery
charge for proper
operation
280 Vdc
Maximum
Operating Points
120 kV, 250mA, 21.75 s
120 kV, 125mA, 43.5 s
30 minute cooling time between maximum scans
Maximum
Deviation from
Indications
Tube Voltage: +/- 1%
Tube current: +/- 2%
Tomogram scan times: User-defined
Topogram scan times: User-defined
Spiral scan times: User-defined
Statement of
Reference Loading
Conditions
Continuous anode input power: 1000 W
Nominal X-ray tube voltage: 120 kVp
Continuous current under this condition: 8.3 mA.
Parameters Range Accuracy
To Next Page
Loading...