How do you evaluate the sensitivity and reliability of different types of developers?

2 Developer sensitivity

The sensitivity of a developer is its ability to produce clear and sharp indications of the defects. The sensitivity depends on several factors, such as the particle size, shape, color, and distribution of the developer, as well as the compatibility with the penetrant and the surface. Generally, the smaller and more uniform the particles are, the higher the sensitivity is. However, too small particles may also cause background noise or false indications. The color of the developer should contrast with the color of the penetrant and the surface. The distribution of the developer should be even and thin, without clumping or cracking.

4 Developer selection

The selection of a developer depends on the specific requirements and objectives of your LPT applications. You should consider factors such as the type and size of the defects you want to detect, the material and shape of the test object, the type and method of the penetrant, the inspection environment and duration, and the safety and environmental regulations. You should also compare the costs and benefits of different developers, as well as their availability and compatibility with your equipment and procedures. You should test and evaluate different developers on representative samples before making a final decision.

5 Developer evaluation

The evaluation of a developer is the process of assessing its sensitivity and reliability using various methods and criteria. The evaluation can be done by the manufacturer, the user, or a third-party organization, depending on the purpose and scope of the LPT applications. The evaluation can include laboratory tests, field tests, or both, depending on the level of confidence and validation needed. The evaluation can use quantitative or qualitative measures, such as the number, size, shape, contrast, and resolution of the indications, or the detection rate, false alarm rate, repeatability, and reproducibility of the results.

6 Developer optimization

The optimization of a developer is the process of improving its sensitivity and reliability by adjusting its parameters or conditions. The optimization can be done by trial and error, experimentation, or simulation, depending on the resources and time available. The optimization can involve changing the type, concentration, temperature, or application method of the developer, or modifying the surface preparation, penetrant dwell time, rinsing time, or inspection time. The optimization can also involve using different techniques or tools, such as fluorescent or color contrast penetrants, ultraviolet or white light sources, magnifiers or cameras, or image processing or analysis software.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?