The Characterization of High-Temperature Paints for Infrared Thermography in Fire Research peer–reviewed journal article has been published in the Fire Safety Journal. The manuscript was authored by the Fire Safety Research Institute (FSRI), part of UL Research Institutes professionals, Grayson Bellamy, fellow, Matt DiDomizio, research engineer, Malhar Patel, intern, and Mark McKinnon, research engineer. Collaborators included the Department of Fire Protection Engineering, University of Maryland, College Park and the Department of Mechanical Engineering, University of Maryland, Baltimore County. This study aimed to provide a reference dataset for researchers to determine optical properties and thermal stability of a set of commercially available paints.

In order to test the thermal stability of the paints, they used thermogravimetry to measure degradation at elevated temperatures. They also used a bench-scale experiment with flame exposure to  demonstrate the accuracy and usefulness of infrared thermography in fire research applications.

The primary objectives of this study include determining if:

• The choice of high-emissivity paint should reflect intended experimental conditions
• Temperature-dependent emissivity characterization reduces IR temperature uncertainty
• IR thermography allows accurate determination of spatialized temperature gradients

This project was internally funded by UL Research Institutes and the journal article can be accessed here.

Abstract:

Infrared temperature measurements are common in fire research and adjacent fields to provide spatially-resolved temperature distributions on surfaces. To obtain accurate temperature values from these instruments, a well-characterized emissive surface is desired to minimize error in the calculated values. In fire applications, the robustness of the surface coating is also an important consideration. To this end, surfaces to be measured with infrared thermal cameras are commonly coated with a high-emissivity coating to reduce uncertainty in measurements. Here, the optical properties and thermal stability of a set of commercially available paints were characterized to assess their suitability for future applications and to provide a reference dataset for researchers. The thermal stability of the paints was assessed using thermogravimetry to measure degradation at elevated temperatures. Emissivity was determined spectrally at room temperature and as a band-averaged value as a function of temperature for long-wave infrared thermography applications. Differences were revealed in these tests, indicating a need to carefully select coatings based on the application, giving consideration to the exposure temperature, optical-sensing band, and dynamic emissivity input for temperature-varying environments. Properties collected were verified against a bench-scale experiment with flame exposure, demonstrating the accuracy and usefulness of infrared thermography in fire research applications.

About Fire Safety Journal: 

Fire Safety Journal is the leading publication dealing with all aspects of fire safety engineering. Its scope is purposefully wide, as it is deemed important to encourage papers from all sources within this multidisciplinary subject, thus providing a forum for its further development as a distinct engineering discipline. This is an essential step towards gaining a status equal to that enjoyed by the other engineering disciplines.