Measuring starts automatically as soon as the sample is placed under the measuring head. The sample is held against the measuring head with the chosen clamping pressure and measurements are taken during the chosen measuring period. It is then released and can be measured in a new position. Everything takes place in one simple measuring sequence.

Measuring compressibility

The compressibility of the paper sample is determined by measuring its surface roughness at two predetermined clamping pressures, thereby simulating the effects of linear loads in various printing methods. Compressibility is reported as a percentage reduction of surface roughness or as a ratio of the two surface roughness measurements.

Function check

It is essential to be able to easily ensure that the instrument is correctly adjusted. Important parameters such as air tightness, zero airflow and clamping pressure can therefore easily be checked by means of a fixed check sequence, after which a report containing set points and deviations from them is generated.

Traceability and reproducibility

Reproducibility is important for all measuring methods. Each L&W PPS Tester is individually calibrated and traceable to Lorentzen & Wettre’s master instrument. This ensures that every L&W PPS Tester and measuring head measures identically within set tolerances. Lorentzen & Wettre uses a master system equipped with six measuring heads that are regularly checked against each other.

L&W PPS Master Kit

L&W PPS Master Kit enables the regular routine checking of all the PPS instruments used by a mill, thereby ensuring that all measurements are fully comparable and reproducible. L&W PPS Master Kit is traceable to Lorentzen & Wettre’s own master system for PPS measuring, thereby guaranteeing reproducibility. The instrument is supplied together with a 1-year subscription which consists of four sets of reference paper samples.