Part 5: What kinds of temperature analysis and report generation are needed?
Up to this point, we have focused primarily on considerations for the infrared camera hardware and data collection, but this is really only half of a system solution. The other half is data analysis and report generation (data sharing). In this section, we focus on defining what data analysis is required for certain applications and what methods are available to share data with colleagues and customers.
FLIR’s temperature-calibrated IR cameras provide a temperature value for each pixel in degrees Kelvin, Fahrenheit, and Celsius. Displaying the image is a great way to quickly see where your target is very hot or cold. Still, techniques for image enhancement, image subtraction, emissivity adjustment, and plotting of charts and graphs can prove even more useful, helping someone really understand the thermal changes taking place on a target object.
The most basic tool used in thermography is image enhancement to adjust the level and span of the image colour palette. This allows you to enhance the image and draw out the subtle temperature differences. Additionally, software that allows for the subtraction of a baseline image from the energized image allows you to remove any reflected ambient temperatures and expose extremely small temperature variances. This technique is critical for objects that are reflective or have a low emissivity.
Other important tools allow the plotting of data in charts or graphs. Examples include: histograms, line profile graphs, and temperature vs. time charts. These graphs and charts help you characterize target heat distribution and temperature changes over time. Figure 6 shows examples of all these analysis tools.
Figure 6: Example data analysis software tools report generation
At some point in an R&D project, the data collected and analyzed will be shared with others. For example, you may want to share raw data with colleagues for additional analysis or share analysis results with customers. As such, it is critical to know who you will be sharing data with and the format they require in order to effectively use your results.
In many instances, custom data analysis with third-party software such as MatLab or Excel is desired. Having an IR software package that allows data export in, for example, a .CSV file is ideal for use in Excel or Matlab. Similarly, data collected over a long period of time is best shared as a data-log file where data is exported in a text file or spreadsheet file-format. Again, this is ideal for importing into third-party software solutions for further analysis.
For management and customers, static images or movie files that can be inserted into emails, slide presentations, or word processor documents will best illustrate IR analysis results. So the ability to export IR sequences and images as .JPG or .BMP files for static imagery and export movies as .AVI or .WMV is a must.
Superframing involves cycling the IR camera through up to four unique temperature ranges and sequentially capturing data from each range. Software, such as FLIR ResearchIR, can then present this data as separate movie files (one movie file for each temperature range), or combine the movie files into a single extended temperature range superframe movie. Superframing only works with certain cameras and software.