Zero Span Test

The web´s fibre strength is measured with the Zero Span Test. Using an initial gage length near zero, a tensile test is performed. Now, mainly the pulp fibres are loaded. 

The Zero Span Test is usually performed with dedicated instruments which are complex and expensive. If Zero Span Test are not frequently required, Zwick´s modular system of grips and accessories offers an affordable solution: For an precise horizontal and angular grip alignment, Zwick offers a mechanical extension kit. The grip already must comply to some minimum accuracy requirements, and this is achieved with pneumatic grips. 

The Zero Span jaws protrude from the grips' inner edge and allow a free span of approximately 0.1 mm. This can only be achieved with numerically controlled machine such as Zwick´s ProLine or zwicki-Line, which guarantee best reproduceability and reduce the risk of danger to a minimum. 

For this test the TAPPI T 231 is the Standard.