What is the purpose of using a linear scale?

Posted by n2stech on January 4th, 2020

Linear scale, also called a graphic scale, bar scale or scale bar.  Linear scale uses the mole strip principle, which uses photoelectric conversion.

The linear scale is composed of main ruler, reading head and interfaces. Generally the line number is according to the measured accuracy, in order to distinguish the direction. Lines are carved from 9 to 0 degree in two ways.

While reading the head movement, the interface circuit of the photoelectric receiver, respectively a, b is two phases at a difference of 90 degree pulse.

The output signal produced by the digital display, resolution is by fine fraction, grating period divided by the number of signals through electrical signal subdivision processing resolution for 5 um or 1 um.

Purpose:

Generally, linear scales are used in architectural and engineering drawings, particularly for those that are drawn after the subject has been built, many drawings do not use a linear scale and such drawings are marked as “Do Not Scale Drawing”. In processing equipments, it is used in areas such as a milling machine, lathe, boring machine, grinding machine, edm machine and thread cutting.  It is also used in measuring instruments such as projectors, video measuring instruments, and tool microscope, also used in numerical control machine tool.