Determination of a property of a fiber suspension
A method for determining a property of a fiber suspension comprises obtaining a sample and diluting the sample by a first dilution, thereby providing a diluted sample, while retaining essentially all of the sample, and mixing the diluted sample, thereby providing a mixed, diluted sample. By removing part of the mixed, diluted sample and retaining an amount of the mixed, diluted sample, further diluting the mixed, diluted sample by adding dilution water to the retained amount of the mixed, diluted sample, thereby providing a further diluted sample, while retaining essentially all of the mixed, diluted sample, mixing the further diluted sample, thereby providing a mixed, further diluted sample, and repeating these steps until the concentration is suitable for measuring the property of the further diluted sample, this property can be measured with high accuracy. A device for determining a property to be determined of a suspension is also provided.
1 . A method for determining a property of a fiber suspension, the method comprising the following steps:
a) obtaining a sample of the fiber suspension,
b) diluting the sample by a first dilution by adding dilution water to the sample, thereby providing a diluted sample, while retaining all of the sample obtained in step a),
c) mixing the diluted sample using a single mixing chamber, thereby providing a mixed, diluted sample, and
d) removing part of the mixed, diluted sample and retaining an amount of the mixed, diluted sample provided in step c),
e) further diluting the mixed, diluted sample by adding dilution water to the retained amount of the mixed, diluted sample retained in step d), thereby providing a further diluted sample, while retaining all of the retained amount of the mixed, diluted sample retained in step d),
f) mixing the further diluted sample provided in step e) using the single mixing chamber, thereby providing a mixed, further diluted sample,
g) repeating steps d)-f) until the concentration of the mixed, further diluted sample is suitable for measuring the property to be determined of the further diluted sample, and
h) measuring the property to be determined of the further diluted sample.
2 . The method according to claim 1 , wherein the property of the fiber is any of the following: fiber length distribution, mean fiber length, content of fines and content of shives.
3 . The method according to claim 1 , wherein, in step d), the amount of the mixed, diluted sample is retained in the single mixing chamber.
4 . The method according to claim 1 , wherein the step f) of mixing comprises imparting a reciprocating movement of a plunger.
5 . The method according to claim 1 , wherein in step a) a sample of a fiber suspension is obtained batchwise.