Measured Half Value Layer (Hvl) At Different Operating Potentials; Line Voltage And Maximum Line Current; Technique Factors For Maximum Line Current; Maximum Deviation - Hologic QDR 4500 Technical Manual

Measured Half Value Layer (HVL) At Different Operating Potentials

Measured operating potential
QDR4500A/SL
80kV
100kV
140kV
QDR4500C/W
80kV
100kV
140kV

Line Voltage and Maximum Line Current

Power
Requirements:
All

Technique Factors for Maximum Line Current

Peak Potential 140kVp
Tube Current 10mA peak, 50% duty factor or 5mA average.

Maximum Deviation

The maximum deviation from the preindication given by labeled technique factor control settings
or indicators are as follows:
Peak Potential: +/- 15%
Current: +/- 40%
Time : +/- 10%

Measurement Criteria for Technique Factors

The measurement criteria of the technique factors is as follows:
Peak Potential: The voltage peak is measured with an oscilloscope. Voltage is a square pulse.
Peak is defined as the peak voltage of the 4 millisecond pulse shape, not
counting any initial overshoot.
Current: Current is measured with an oscilloscope on the last millisecond of the 4
millisecond pulse.
Time: Time of each pulse is measured with an oscilloscope and defined as the time
between 50% rise and fall times of the peak potential pulse. Time of the scan
is measured by counting the number of AC line pulses from the start to the
end. X-ray pulses are synchronous with the AC line.
Section 1 - Introduction
Measured Half Value Layer
3.7mm Al equivalent
4.7mm Al equivalent
7.2mm Al equivalent
3.7mm Al equivalent
5.0mm Al equivalent
6.5mm Al equivalent
100VAC 16A 50/60Hz, Max apparent resistance = 0.32 ohm
120VAC 14A 50/60Hz, Max apparent resistance = 0.32 ohm
230VAC 8A 50/60Hz, Max apparent resistance = 1.28 ohm
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