The proper selection of relevant analysis and test methods for raw materials, inter¬mediate or final products obviously has importance for the success of a testing program. Process and product analysis are the main areas for a large variety of very heterogeneous testing methods. Process analysis tries to define the control varia¬bles of the process that allow it to run smoothly and produce products with the necessary properties. The aim of product analysis is to define the properties that relate to the use of a specific product or material.
The test results obtained should be representative for all of the paper from which the sample has been taken. Reliable, representative measuring results require
. • representative sampling as far as quality and quantity are concerned
. • adequate sample preparation
. • calibrated measuring equipment
. • careful, accurate measuring.
A straightforward process for cut-size and reel paper is described in ISO 186 (2002).
As a result of its hygroscopic properties, paper and board must be tested under standard climatic conditions and the samples must be conditioned in this climate for at least 4 hours before testing (sample conditioning). In ISO 187 (1990), the preferred climate for paper testing is specified as 23 °C and 50 % relative humidity. In the following the most relevant test methods for paper and board testing will be described.