HPIR Transmission moisture measurements

Excellent moisture measurement is critical to papermaking because almost every controllable parameter on the paper machine has an impact on moisture. HPIR measurement provides the most precise tool available to measure moisture with the confidence needed to maximize control performance while saving on energy and fiber costs. 

Precision means confidence
With our High-Performance Infrared (HPIR) sensor’s highly precise moisture measurement, mill operators can confidently use CD control for faster start-ups and grade changes. Papermakers can shift their moisture targets closer to acceptable quality limits, saving energy and reducing fiber costs while remaining within the paper grade’s quality specifications. Precision depends heavily on the number of measurements made within each databox. HPIR sets a new standard for this precision by calculating measurements 5,000 times per second. The result is less measurement noise per databox. HPIR also continues the industry-leading accuracy performance of ABB moisture measurement across the full range of a customer’s paper grades.
High resolution for greater insight
Moisture streaks in a paper machine’s cross direction often indicate there are problems with felts, wires, coating stations or CD moisture actuators. High resolution moisture measurement resolves these streaks, and can also help system engineers define a better process model for improved CD control performance. The HPIR sensor measures moisture streaks as narrow as 4 mm and displays them clearly on the ABB QCS profile displays and contour maps.

Broadband performance advantage
Until now, infrared moisture sensors have been designed to mechanically block the measurement beam at high frequency to suppress background radiation. Known as beam chopping, this method reduces signal-to-noise ratio by a minimum factor of two. In addition, the chopping frequency places a fundamental Nyquist frequency limit on the measurement bandwidth. HPIR measurement is different – it does not chop. While measuring, HPIR continuously measures and simultaneously compensates for background radiation, boosting signal and measurement rate. This combination of high spatial resolution and high measurement rate ensures that HPIR does not miss anything while providing an accurate and precise measurement of transient moisture features.

Elegant simplicity
A more reliable and robust sensor design means less paper machine downtime for troubleshooting or swapping sensors. HPIR is air-cooled and has no continuously moving parts. The sensor’s modular design allows for field replacement of modules, avoiding repairs at the manufacturer’s shop, and eliminating the need to stock a complete spare sensor.


  • Minimum 5,000 moisture calculations per second
  • True edge-to-edge measurement within 1 cm of the edge
  • Continuous measurement while scanning with no beam chopping 
  • Small measurement spot size (4mm)
  • Temperature control of detector and source assemblies (no water-cooling)
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