NEMA XR 5-1992 (R1999)

Foreword
Scope
1 Definitions
2 Slit camera method of measurement
     Basic method
     Slit camera
     Imaging procedure
     Photographic technique
     Electrical conditions
     Measurement of x-ray image
     Statement of compliance
3 Focal spot blooming
     Exposure factors
     Measurement procedure
4 Resolution camera (star pattern) method of evaluation
     Basic method
     Star pattern camera
     Radiographic film
     Photographic technique
     Electrical conditions
     Determination of focal spot resolution
5 Pinhole camera method of evaluation
     Introduction
     Basic method
     Pinhole camera
     Photographic technique
     Electrical conditions
     Method of observation
6 Measurement correlation
     Introduction
     Basic method
     Applicable dimensions
7 Determination of modulation transfer function (MTF)
   of the focal spot
     General information
     Measurement
     Calculation of the MTF
Tables
2-1 Test conditions
2-2 Focal spot size tolerance limits (for slit camera
     method)
3-1 Test conditions (blooming)
5-1 Pinhole diaphragm dimensions
5-2 ENLARGEMENT FACTOR (E) for pinhole camera
7-1 Standard magnification of MODULATION TRANSFER
     FUNCTIONS
Figures
2-1 Slit diaphragm
2-2 Evaluation directions for focal spots
2-3 Amount of contribution to image size due to slit
     width
2-4 Imaging geometry
2-5 Determination of ENLARGEMENT FACTOR (E)
2-6 Tube nameplate
4-1 Essential dimensions of the test pattern
4-2 Alignment of the star pattern camera
4-3 Image of the test pattern
5-1 Cross-section of pinhole diaphragm
6-1 Correlation geometry for EFFECTIVE FOCAL SPOT
     length determination
6-2 Projection of the ACTUAL FOCAL SPOT over the
     radiation field
7-1 Microdensitometer scan
7-2 Limitation of input data

Gives test methods for assessing the properties of focal spots for medical diagnostic x-ray tubes but is not intended for use with x-ray tubes used in computed tomography (CT) scanners.