Kodak Guide to Manual Processing of NDT Films PDF Technical Data Manual

To reach the desired density on a radiograph, many people use set exposure factors and then adjust development time— or “sight develop”—to compensate for under- or overexposed images. Today, you can eliminate that guesswork and get more consistent results by using KODAK INDUSTREX Films with our exclusive T-GRAIN Emulsion technology. The key is to use the correct exposure factors when you shoot the images. We provide handy KODAK NDT Exposure Calculators to help you determine the right factors for each situation.

By removing the processing variable, you will get better consistency and higher productivity in the darkroom. Our films provide stable contrast and a relatively stable speed over a wider range of developer temperatures—unlike older film technologies that have highly variable speed, relative to
developer temperature and immersion time. When using an Ir-192 source, you can use the KODAK NDT Exposure Calculator to determine correct exposure (based upon density desired). Then follow these simple processing recommendations. Timer and Thermometer The Time and Thermometer are essential. They must be accurate and in good condition.

Safelight
Use a KODAK LED Safelight (660nm red) or a red safelight filter (i.e. KODAK 1, 1A, or 2 Safelight Filter) in a suitable safelight lamp equipped with a 15-watt bulb. Keep the film at least 4 feet (1.2 metres) from the safelight. Note: Other safelight filters (i.e. KODAK 8 and GBX-2 Safelight Filter) which block radiation at 550nm and shorter wavelengths are also suitable for use. Film Handling Do not bend the film. Handle the film only by the edges to avoid finger marks and abrasions when loading on hangers.Separate the hangers in solutions so that films will not touch each other or the tank wall.

ENSURING PROCESS QUALITY
Residual Thiosulfate Test To ensure good keeping characteristics for radiographs, use a test kit such as the KODAK Hypo Test Kit (CAT 196 5847). This test determines whether film has been adequately washed and provides an estimate of the archival life you can expect. The kit comes complete with testing solution and a visual estimator. Residual Silver Test Solution An overworked fixing bath contains complex silver thiosulfate compounds that cannot be removed completely by washing. KODAK Residual Silver Test Solution ST-1 provides a quick and accurate method for determining when a fixing bath should be discarded.

To Use: Store stock solution in a small stoppered bottle not more than 3 months. Dilute 1 part stock solution with 9 parts water. (Replace working solution weekly.) Place a drop of ST-1 Solution on the margin of processed film. Remove solution after 2 to 3 minutes. Any yellowing of test area indicates the presence of silver. Refix film in fresh fixer and rewash. The yellow stain is permanent. To 5 drops of KODAK Fixer Test Solution, FT-1, add 5 drops of the fixing bath and 5 drops of water. Discard the fixer if a yellow-white precipitate forms instantly. (Any slight milkiness can be disregarded.) You can also use Silver Estimating Test Papers to measure the silver content in your fixer. One supplier is USI International, Inc. (www.silverprofit.com).

KODAK NDT Exposure Calculator
The KODAK NDT Exposure Calculator eliminates guesswork in determining the proper exposure and processing when using an Ir-192 source. It provides the proper exposure for a given material thickness, distance, source strength, and development*. Today, many shots are lost due to sight adjustment of density during the development cycle, so we removed the development variable to make your results more consistent. But again, getting the proper exposure is critical—so use the calculator for the correct factor for your situation.

Download Kodak Guide to Manual Processing of NDT Films PDF Technical Data Manual


February 24, 2010 | Posted in Electronic Manual, Kodak Manual

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