The new Metso IQ Optical Caliper sensor offers improved accuracy on low opacity papers
All papermakers can now benefit from improved runnability with confidence in quality provided by the sub-micron profile accuracy of the new Metso IQ Optical Caliper measurement.
The new sensor has been operating for several months at a leading Scandinavian mill with no problems on low opacity papers. Janne Sällilä of Metso, says, “The conventional laser penetrates deeply into the siliconized paper. The customer wanted to measure the total caliper of both fibers and silicon together. This new sensor provided the answer and the mill reports much smoother profiles. Its self cleaning head has also provided a maintenance advantage over the previous sensor which had to be cleaned regularly. ”Mills producing low opacity grades such as greaseproof paper can now take advantage of a new development in optical caliper measurements by Metso.
Optical measurements have become accepted technology to avoid the sheet pinching effect experienced with contacting caliper measurements; but due to the conventional measurement technology, light penetration of the sheet can undermine accuracy with low opacity or porosity grades.
Metso has been quick to take advantage of the latest developments in new technology that through the improved light scattering of the shorter wavelength light, and new detection technology, eliminates errors due to light penetration. As there are no pinching parts that could cause holes or sheet breaks.
IQ Optical Caliper combines two accurate measurement techniques. The magnetic principle is used to measure the distance of the optical measurement to a reference plate while the non-contacting optical principle measures the distance to the paper surface. Paper thickness is reached by subtracting these individual measurements from each other. As well as the use of the blue light source (patent pending) to solve light penetration problem, the new self cleaning construction of the sensor head (patent pending) eliminates one further difficulty experienced with conventional laser sensors.
Metso IQ is a combination of intelligent scanning, high-speed quality measurements, robust multivariable controls and the analysis toolbox unleashes a set of diagnostic capabilities that alert the operators to potential sources of problems and provides them with the necessary information online so they can run the machine better.