ASTM E1815 Standard Test Method for Classification of Film Systems for Industrial Radiography

Get Certified ASTM E1815 Testing for Reliable Radiographic Film Performance 

For industrial radiography, images produced under each production batch and processing condition must have equal quality. Certified ASTM E1815 testing confirms that a film system delivers the gradient, granularity, and speed characteristics associated with a specific system class. Radiographic film and developer chemistry manufacturers and contracting parties use this classification to agree on the film image qualities a system can produce. Regular testing is helpful to quality control and to prevent inconsistent film performance from creating inspection failures. 

• Material Type: Direct-exposure industrial radiographic film system.
• Application: Classifying film system performance relative to each other.
• Measures taken in property: Gradient, gradient/noise ratio, and granularity.
• Method: X-ray exposure against a density measurement and microdensitometer scanning on a tungsten target.
• Result: Film system assigned a class based on a published classification table.
• Test Limitations: Applicable only to direct exposure-type film with lead intensifying screens, not fluorescent-type screens.
• Environmental conditions: Processing chemistry and development conditions affect the measured film system performance.
• Applications: Radiographic film manufacture, developer chemistry qualification, and weld and casting inspection specification. 

What are the Uses of ASTM E1815 Testing?

The standard is critical to the aerospace, automotive, construction, and energy industries in evaluating and qualifying non-destructive radiographic film systems based on safety and quality standards.

What Materials Can Be Tested Under ASTM E1815? 

It tests for structural reliability in metals such as steel, aluminum, and titanium, composite materials, and weldments. In radiographic inspection, internal flaws are detected so that the results comply with industry standards.

Why is ASTM E1815 Important? 

The standard method is important for the faithful reproduction of quality images within radiographic film systems, for defect detection, quality assurance protocols, and improvement of the reliability and safety of the final product.

ASTM E1815 Testing Process and Data Collection

The analyst chooses a representative film system (film and processing chemistry) for evaluation. Then, the technicians expose the film samples to the X-rays from the tungsten-target tube and process them under the specified conditions. The operator takes the density readings of a film at a series of known exposures to form a density vs. exposure curve. Technicians also scan a uniformly exposed film sample with a microdensitometer to measure granularity. Finally, analysts determine the gradient, the gradient/noise ratio, and the classification requirements for the standard, and compare all three to the standard. 

Common Challenges and Troubleshooting

Image quality and film processing variability are some of the challenges encountered in testing. Troubleshooting involves problems with inadequate exposure, improper handling, and chemical processing deviations. Calibration and adherence to test parameters must be ensured to obtain reliable results.

• The laboratory reports gradient values at specified density levels above base plus fog and records the corresponding density levels used for evaluation.
• Analysts report the gradient-to-noise ratio at the specified density level and record the applicable measurement conditions.
• Engineers evaluate granularity using microdensitometer scanning and report the measured granularity value according to the applicable procedure.
• Analysts assign the film system to the applicable class when all required gradient, gradient-to-noise ratio, and granularity criteria fall within the specified limits.
• The report also includes additional speed information for reference alongside the film-system classification.

Link to ASTM E1518