Valmet IQ X-Ray Ash Measurement

Valmet IQ X-Ray Ash Measurement (IQ X-Ray Ash) measures calcium carbonate, clay and titanium dioxide individually, and total ash as a summary of above mentioned filler components.

This ash constituent analysis provides a solid base for controlling each component in the papermaking furnish. Digital signal processing, high-speed air density temperature compensation and dirt buildup compensation ensure superior sensor accuracy even in hot, humid and dirty papermaking environments. IQ X-Ray Ash is factory pre-calibrated for papers containing varying amount of total ash levels.


X-ray radiation provided by a X-ray tube is absorbed preferentially by the inorganic material in a paper sheet. X-ray tube produces X-ray radiation when energized. Radiation intensity is measured with large area PIN detectors, electrometer preamplifiers and associated electronics.

Principle of the measurement is based on absorption of low energy x-ray radiation in the measured material. Total ash and amount of different ash components can be calculated from X-ray tube radiation spectrum and ash component specific absorption ratios.

The effects of air density changes are measured and automatically compensated using high-speed air gap temperature measurements. In addition, internal temperature measurements within the source and detector heads are used for diagnostic purposes.


  • More accurate and stable onsheet measurements for precise control of ash and related quality properties.
  • Ash content and composition can be optimized to improve quality and reduce furnish cost.
  • Faster on-spec quality and reduced startup waste.