The Hartmann tuning fork is used as a medical instrument, particularly in the field of neurology. The tuning fork is used to test sensory and nerve function, particularly in the feet and legs, by striking it against a surface and then placing the vibrating prongs on various points on the skin. The vibration of the tuning fork stimulates nerve fibers in the skin and the response can be used to evaluate the function of certain nerve pathways, as well as to diagnose conditions such as peripheral neuropathy, nerve compression, and nerve damage. The Hartmann tuning fork is a simple and non-invasive tool that can provide valuable information about the health of the nervous system.