BALL penetration probes suitable for compression penetration tests on fruits, vegetables and other foodstuffs. Two fundamental criteria for a good test are repeatability and resolution for comparison between results. In many cases where sample hardness / softness is required, a ball probe can provide repeatability and resolution. The principle of the spherical probe is that the uniform compressive force is distributed at a normal angle with respect to the surface area of the ball. This gives an average effect on the local area being tested.