SMOOTHNESS – Bekk
Purpose of the test
This test is performed to determine the smoothness of paper, solid board or folding board according to Bekk.
Procedure
Operate the instrument in accordance with ISO 5627 and the manufacturer’s instructions.
Leave the samples exposed for 24 h to 23°C and 50% R.H., according to ISO 187.
Determine the smoothness of 10 test pieces, one value per test piece with its marked side turned towards the air flow.
Report 10 measures in s, their mean and standard deviation calculated to 3 significant figures.
ISO 5627
Nr. of samples
12 test pieces per level
Special size A4
Levels
Level 1: 25.0÷40.0 s
Level 2: 120÷160 s
Level 3: 200÷300 s
Level 4: 1300÷2000 s
Reporting
Report 10 valid results of measurements in s, their mean and their standard deviation. All to three significant digits.