Paper Porosity Online Profiling

摘要

The sensor design is based on the measurement of airflow,which correlates directly with sheet porosity.The sensor controls contact with the sheet,and-by using a small controlled measuring vacuum-creates airflow through the paper.This measurement approach emulates laboratory methods,and is linear not grade dependent-thus minimizing calibration efforts.The sensor ensures the accuracy of porosity measurements by eliminating the effects of dust and leakage air-air travelling with the sheet or air that has not travelled through the sheet.The sensor maintains good contact between the measuring head and web by means of an outer vacuum ring,which prevents air leakage.