844 N- For measuring of diameter, roundness and conicity of bores as well as distances
Features
Measuring the diameter, roundness and conical form of a bore as well as the distances of plane-parallel surfaces. Measuring head consists of a carbide-tipped moving anvil and an interchangeable stationary anvil which has a hardened steel ball; alternatively a carbide ball is available. Transmission lever system transfers movement of the movable anvil to indicating instrument. The broad centering bridge ensures automatic centering in the bore. Insensitive to temperature due to both the shank and transfer rod being made from heat resistant Invarsteel. Highly resistant to wear and tear due to the carbidetipped moving anvil. Constant measuring force due to built-in spring thus eliminating user influence. Universally applicable and extremely versatile as every instrument spans a broad measuring range, within this range it is quick and easy to adjust to any size.
	Invar steel has a particularly low expansion coefficient and thus makes the instrument totally insensitive to any kind of heat. Body heat from the user, increases in ambient temperature have no influence on the measuring results. The graph on the right compares the Invar steel version to a standard type. Both gages were hand-held and thus influenced by body heat. The deviation when using Invar steel is negligible.