Textile Testing

Step 1: Analyze each term in List I and find its corresponding principle or instrument in List II.
- A. Tear strength: This measures the force required to propagate a tear in a fabric. A common method to test this is the Elmendorf tear tester, which works on a falling pendulum or impact principle.
- B. Water repellency: This measures a fabric's ability to resist wetting. The contact angle test, which measures the angle a water droplet makes with the fabric surface, is a direct way to quantify surface wettability and repellency. A higher contact angle means higher repellency.
- C. Seldom occurring faults: These are large, infrequent yarn faults (like slubs or long thick/thin places) that are not captured well by standard evenness testers. The Classimat is an instrument specifically designed to classify and count these seldom-occurring or "objectionable" faults.
- D. Spectrogram: A spectrogram is a graphical output from a yarn evenness tester. It plots the amplitude of mass variation against its wavelength, making it the primary tool for identifying periodic faults.

Step 2: Assemble the correct matches.
- A III - B I - C IV - D II

Step 3: Find the corresponding option. The combination A-III, B-I, C-IV, D-II matches option (C). (Note: There is a typo in option D, it's identical to C).

Step 1: Understand the Kawabata Evaluation System (KES-FB). This is a set of standardized instruments designed to objectively measure the low-stress mechanical properties of fabrics that relate to the subjective feeling of "hand" (e.g., softness, stiffness, smoothness). The system consists of four main instruments.

Step 2: Identify the properties measured by each instrument.
- KES-FB1 (Tensile and Shear Tester): Measures properties related to stretching and shearing the fabric. This includes tensile strain, linearity of the load-elongation curve (A), and tensile energy (C). - KES-FB2 (Pure Bending Tester): Measures how a fabric resists bending. This gives bending rigidity or stiffness (D). - KES-FB3 (Compression Tester): Measures the properties of the fabric when it is compressed. This includes thickness, compressibility, and compression resilience (B). - KES-FB4 (Surface Tester): Measures surface friction and roughness.

Step 3: Evaluate the listed properties. All four properties listed (A, B, C, and D) are standard parameters measured by the different modules of the KES-FB system. Therefore, all are correct.