Beyond just identifying the frequency, deeper analysis is possible by using the channel-specific information available from Tapio Measurements. Tapio Analyzers measure the same point in paper with multiple sensors with small apertures and high resolution.

Available sensors include:

• Basis weight
• Caliper
• Ash content (absolute and relative)
• Gloss (both sides)
• Transmission
• Remission (optical brightness)
• Porosity

Additional calculated channels based on combining the data from multiple sensors, such as density, bulk, relative ash.

By analyzing in which measured property (channel) the fault appears, and studying correlations between channels, it becomes possible to narrow down the likely source of the problem, using reasoning that depends on knowledge of the specific production line:

• Basis weight defects typically originate from the wet end of the paper machine, where the basis weight is formed.
• If ash content is not evenly distributed relative to basis weight (poor correlation), the source may lie in the coating stations.
• Gloss variations that occur at the same frequencies as thickness variations usually indicate problems originating from the calendering sections.

By combining frequency and correlation analysis with reasoning based on the defect type and measurement channel, maintenance and troubleshooting efforts can be much more targeted and effective.