At-Line Analysis of Coat Weight on Steel and Aluminum Sheets with ED-XRF Spectroscopy
Producers of steel or aluminum sheets often coat their products to protect them from rust or corrosion or to achieve a variety of objectives. The sheets go through a number of chemical processes to convert the steel or aluminum into the coating material and consistency of coating thickness — commonly referred to as “coat weight” — is vital to successful production quality and requires advanced analytical techniques. Depending on substrate and customer requirements, analytical instruments might have to detect and measure the thickness of a wide variety of coating materials.
X-ray fluorescence (XRF) spectroscopy is an excellent technology for coat-weight analysis and can be performed with a variety of instruments, ranging from handheld systems to laboratory based WD-XRF cabinets. Laboratory instruments are expensive and can delay process schedules, as samples must be run back and forth from lab to line. Handheld XRF systems have been popular but have many practical and analytical drawbacks.
This paper explains how a new generation of portable ED-XRF instruments can provide performance comparable to lab-based systems and offer the flexibility to be easily moved to various process points to provide high accuracy QA/QC.