the measured object referring again to fig3 and 4 lock end 6 includes contacts 13 that communicate with corresponding contacts 14 provided in a microprocessor 15 housed within frame 1 of the measuring device portion of the diameter measuring system the sensor probe of the sensor assembly generates an output signal indicative of the extended position of the probe tip 10 a and the microprocessor receives the sensor output signal via contacts 13 and 14 microprocessor 15 is programmed to process and digitize the output signal from the sensor probe and generate a digital display 16 that provides a readout in either english units 17 or metric units 18 as illustrated in fig1 and 1a the readout corresponding to the diameter of the object being measured it is well known that micrometers and the like have a limited diameter measuring range typically one inch diameter increments for example a one inch micrometer to measure one inch diameter and smaller round stock a two inch micrometer is used to measure rounds between one and two inches in diameter and so on such one inch measuring increments makes it necessary to purchase a wide range of different micrometers in order to meet various job requirements in a machine shop operation in instances where a machine shop is manufacturing or refurbishing large diameter products for example working rolls and backup rolls used to manufacture metal.