Which load range is applied during the Knoop hardness test?

The Knoop hardness test utilizes a specific range of loads to measure the hardness of materials, which is particularly effective for brittle materials and thin sections. The correct answer indicates that the load range is from 1g to 120kg. This broad range allows for precise hardness measurement across various materials, particularly useful in applications where different material hardnesses are critical, such as in metals, ceramics, and composite materials.

Using lighter loads (down to 1g) enables the test to be sensitive enough to measure softer materials or delicate coatings without causing damage, while applying loads of up to 120kg provides the capability to accurately assess harder materials. This flexibility ensures that the Knoop hardness test can be adapted for different sample sizes and material types, allowing for accurate and meaningful comparisons of hardness across a wide spectrum of materials.

In contrast, other load ranges mentioned lack the versatility needed to accommodate the diverse materials assessed in practical applications of the Knoop hardness test.