UNE-EN ISO 13938-2: 2019

• Test surface: Surface of the specimen included inside the ring clamping device.
• Burst pressure (pressure at burst): Maximum pressure applied to a specimen fixed on a membrane below until the specimen ruptures.
• Burst Strength (Burst Strength): Pressure obtained by subtracting the membrane pressure from the mean burst pressure.
• Membrane Pressure: Pressure applied to the membrane, without the specimen, to deform it to the mean burst strain of the specimen.
• Burst Strain (Deformation at Burst): Expansion of a specimen at burst pressure.
• Burst height: Distance between the upper surface of the specimen before deformation and the same surface at the moment of burst pressure.
• Burst time: Elapsed time to deform a specimen until bursting.

A test piece is fixed to a membrane by means of a clamping ring. An increasing fluid pressure is applied to the underside of the membrane, causing deformation of the membrane and tissue. The volume of fluid is increased at a constant rate per unit of time until the bursting of the specimen. The burst strength and deformation are determined.

• The burst pressure must be indicated with an accuracy of ±2% of the full scale value.
• The burst height up to 70 mm must be indicated with an accuracy of ±1 mm
• A test surface of 50 cm2 (79.8 mm diameter) should be used.

Other test surfaces of 100 cm2 (112.8 mm diameter), 10 cm2 (35.7 mm diameter) and 7.3 cm2 (30.5 mm diameter) may be used if the preferred surface cannot be applied with existing test equipment or in the case of high or weak tissue expansion, different tissue requirements

• The membrane must meet the following requirements:
• maximum thickness of 2 mm;
• high expandability;
• if the same membrane is intended to be used several times, it must be elastic in the range of burst heights observed during the test

• Conditioning according to ISO 139
• A test area of ​​50 cm2 is prepared
  For most fabrics, mainly knitted fabrics, it is possible to use the test area of ​​50 cm2. For fabrics with low extensibility (known from previous experiences or previous tests), forFor example, fabrics for technical uses, a test area of ​​100 cm2 is recommended.
• The apparatus is regulated at a constant rate of volume increase, situated between 100 cm3/min and 500 cm3/min.
• The test piece is placed flat on the membrane without stress or deformation in its own plane and is adjusted to the zero position.

• Pressure is applied to the specimen until the tissue bursts.
• Immediately after the burst, if the burst occurs near the restraint, it should be noted. Jaw breaks that occur within 2mm of the clamping line should be rejected. The assay is repeated at least four times at different tissue sites
• For wet tests, the specimen is left submerged for 1 h in water in accordance with EN ISO 3696:1995 at a temperature of (20 ± 2) ºC.

• Mean burst strength: Calculate the arithmetic mean of the burst pressure in kilopascals.
• Mean burst height: Calculate the arithmetic mean of the burst height in millimeters
• Mean burst volume: Calculate the arithmetic mean of the burst volume in cubic centimeters
• Coefficient of Variation: Calculate the coefficient of variation and 95% confidence limits for burst pressure, burst height and, if necessary, burst volume.
• 95% confidence limits in units of the corresponding mean values, if necessary.
• EN11612 requirements:
  • • 100 kPa Area 50 cm2
    • 200 kPa Area of ​​7.3 cm2