Radiography in Modern Industry - Kodak

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The radiograph should be placed in a heavy manila envelope of the proper size, and all of theessential identification data should be written on the envelope so that it can be easily handled andfiled. Envelopes having an edge seam, rather than a center seam, and joined with anonhygroscopic adhesive are preferred, since occasional staining and fading of the image iscaused by certain adhesives used in the manufacture of envelopes. Ideally, radiographs shouldbe stored at a relative humidity of 30 to 50 percent.See "American Standard Requirement for Photographic Filing Enclosures for Storing ProcessedPhotographic Films, Plates and Papers," PH1.53-1978, or the latest revision thereof. Availablefrom American National Standards Insitute Inc., 1430 Broadway, New York, NY 10018.Radiography in Modern Industry 120
Chapter 11: Process ControlUsers of industrial radiography must frequently meet requirements of density and sensitivity setforth in inspection specifications. They must also keep the radiograph rejection rate to aminimum. Control of variability in both exposing and film processing is essential if theserequirements are to be met. Although exposure and processing are the most frequent sources ofsignificant variations, other factors, such as intensifying screens and film, also contribute toradiographic variability.The exposure of industrial x-ray film to energy in the visible spectrum is not a reliable indicator ofthe process level or the repeatability of exposures to x-radiation. Therefore, exposure of thecontrol film to white light is not a satisfactory tool for controlling process variability in industrialradiography. In the procedure for controlling either the exposing unit or the film processing, orboth, described here, x-radiation is used to expose the control film.The data obtained from exposures to x-radiation can be utilized in many ways. The procedure issimple and not only reveals both exposing and processing variations but also differentiatesbetween them. It can be customized to fit specific requirements; a few suggestions for doing soare presented later. No attempt has been made to list all the measures available for reducingvariations in density inasmuch as the procedures required for adequate process control dependon the conditions in the laboratory and production specifications.Equipment And MaterialsMost of the equipment and the material needed to set up a meaningful program of processcontrol is readily available to industrial radiographers. The key items are:Electronic Direct-Reading DensitometerAccurate, precise densitometers capable of measuring diffuse density are available from dealersin photographic supplies.Calibrated Film StripThe strip is used to check the precision of the densitometer. If one is not available, a control stripon which previous readings have been recorded will suffice.Stepped WedgeThe wedge should be made of steel or the material most often tested. One step should be thickenough to permit the passage of radiation sufficient to produce a density of 0.6 to 1.0, anotherstep should be thin enough to permit passage of twice as much radiation to produce a density of2.0 or higher. Although not essential, it is helpful if the difference in the density produced byadjacent steps is uniform.FilmA box of industrial x-ray film of the type most frequently used in the normal production operationshould be reserved for the control program. Before all the film in this box has been used, a newbox should be reserved for the same purpose and the necessary data on the response of the newfilm should be obtained.RefrigeratorAfter exposure, control strips must be stored at 40°F (4.5°C) or lower. When the stock of controlfilm exceeds a six-week supply, the unexposed film should be stored in a refrigerator and nomore than a one-week supply should be removed at any one time. When the temperature and thehumidity are high (more than 75°F or 24°C and 50 percent relative humidity), unexposed filmshould be refrigerated regardless of the size of the stock.
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RadiographyinModernIndustry
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RadiographyinModernIndustryFOURTH E
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ContentsIntroduction...............
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Chapter 1: The Radiographic Process
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Intensifying ScreensX-ray and other
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makes it a very suitable material f
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Figure 6: Typical voltage waveforms
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Table I - Typical X-ray Machines an
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The wavelengths (or energies of rad
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Table III - Industrial Gamma-Ray So
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1. The source of light should be sm
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B and H in the Figure 13 show the e
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Figure 14: Geometric construction f
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Figure 17: Pinhole pictures of the
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The kilovoltage applied to the x-ra
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Figure 21: Schematic diagram of som
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kind of material radiographed, the
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instance, the kilovoltage may be fi
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The technique need not be limited t
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Chapter 5: Radiographic ScreensWhen
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Contact between the film and the le
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Figure 29: The number of electrons
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lead foil screens ran be retained w
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Figure 33: The sharpness of the rad
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Figure 34: Low density (right) is a
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such as a wall or floor, on the fil
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from this source. Since scatter als
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A filter reduces excessive subject
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Definite rules as to filter thickne
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0.010-inch front screen of value be
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Example: Suppose that with a given
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If the milliamperage remains consta
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espectively. In other words, a cons
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Any given exposure chart applies to
Page 69 and 70: Figure 46: Typical gamma-ray exposu
Page 71 and 72: where the slope of the characterist
Page 73 and 74: Figure 49: Characteristic curves of
Page 75 and 76: Figure 51: Characteristic curve of
Page 77 and 78: Nomogram MethodsIn Figure 54, the s
Page 79 and 80: Figure 56: Transparent overlay posi
Page 81 and 82: Figure 58: Overlay positioned so as
Page 83 and 84: The problem of radiographing a part
Page 85 and 86: Figure 62: System of lines drawn on
Page 87 and 88: Chapter 8: Radiographic Image Quali
Page 89 and 90: Film contrast refers to the slope (
Page 91 and 92: Hole Type PenetrametersThe common p
Page 93 and 94: of the same thickness as the specim
Page 95 and 96: Chapter 9: Industrial X-ray FilmsMo
Page 97 and 98: Figure 70 indicates the direction t
Page 99 and 100: the lead letters on a radiation-abs
Page 101 and 102: Therefore, protection requirements
Page 103 and 104: 5. Avoid pressure damage caused by
Page 105 and 106: Paddles or plunger-type agitators a
Page 107 and 108: slow, and the development time reco
Page 109 and 110: ubbles make their way to the surfac
Page 111 and 112: When development is complete, the f
Page 113 and 114: soften considerably with prolonged
Page 115 and 116: Figure 77: The roller transport sys
Page 117 and 118: Rapid Access to Processed Radiograp
Page 119: Figure 78: Film-feeding procedures
Page 123 and 124: 3. Age of the developer replenisher
Page 125 and 126: Figure 80: Control chart below for
Page 127 and 128: DiscussionDensitometric data and pr
Page 129 and 130: Figure 82: Plan of a manual x-ray p
Page 131 and 132: Figure 83: A schematic diagram of a
Page 133 and 134: loading-bench activities are carrie
Page 135 and 136: KODAK Quinone-Thiosulfate Intensifi
Page 137 and 138: Methylene-Blue MethodTwo variations
Page 139 and 140: KODAK Hypo Test Solution HT-2Avoird
Page 141 and 142: In summary, use of the test papers
Page 143 and 144: narrow angle would be very thick, e
Page 145 and 146: When radiation passes through a spe
Page 147 and 148: Figure 89: Demonstration of the eff
Page 149 and 150: Figure 90: The amount of gamma radi
Page 151 and 152: The radiograph exposed in the right
Page 153 and 154: To illustrate, let us assume that t
Page 155 and 156: Figure 95: High-speed x-ray picture
Page 157 and 158: Figure 97: Two methods of neutron r
Page 159 and 160: Duplicating RadiographsSimultaneous
Page 161 and 162: Sometimes, as when sets of referenc
Page 163 and 164: PhotofluorographyIn photofluorograp
Page 165 and 166: discontinuities or of segregation i
Page 167 and 168: from the camera or by reaching down
Page 169 and 170: Figure 106: Schematic diagram of th
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valuable technique, for instance, i
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The position of the spots is determ
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Powder Diffraction File, Internatio
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Processing TechniquesRadiographs on
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Since this formula applies only to
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such that it does not distort the i
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Figure 113: A: Representation of a
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Figure 115: Characteristic curve of
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film fairly well. If high densities
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Density = 1.5 Density = 2.5Film Rel
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In most industrial radiography, the
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e noted here. Although the average
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Chapter 17: Film Graininess; Signal
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The ratio of signal to noise has a
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Chapter 18: The Photographic Latent
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Thus, the change that makes an expo
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Figure 130: Stages in the developme
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electrons by successive Compton int
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Development is essentially a chemic
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Chapter 19: ProtectionOne of the mo
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duct is brought into the x-ray room
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Radiography in Modern Industry - Kodak

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