LG2

The Logitech LG2 is an autocollimator in the test and measurement category. The Logitech LG2 is a highly accurate angle measuring device used in the production of parallel specimens. The Logitech LG2 is intended for measuring small angles, internal and external angular measurement of porro prisms, and testing for wedge difference. The Logitech LG2 is suitable for use with a wide range of sample types and holding fixtures, and is particularly suitable for use with Logitech PP5 series polishing jigs. The Logitech LG2 has a typical setting accuracy better than 2 arc seconds, a 30 mm aperture, optical reference flatness of Lambda/8, an adjustment range of ±25 minutes of arc, and a 90-260 V, 50-60 Hz power supply.^[1][2]

The Logitech LG2 focuses light through a dark field graticule. The Logitech LG2 passes the beam through X and Y axes optical datum adjustment plates and reflects the beam by a mirror through the objective lens onto the upper surface of the specimen being examined. The Logitech LG2 then reflects the image onto another mirror, which projects it through a light field graticule into the eyepiece. The Logitech LG2 uses this optical path to set the specimen surface in relation to the plane of an optical reference surface and to measure angular deviation.^[2]

The Logitech LG2 is set up by first placing the X and Y axes adjustment controls at their mid-range positions. The Logitech LG2 then uses three optical datum adjustment screws on the base of the stand to bring the image into alignment with the field of view. The Logitech LG2 uses the X and Y axes adjustment to bring the bright and dark field graticules into exact coincidence as viewed through the eyepiece. The Logitech LG2 may be used with alternative specimen holders by retaining the optical reference standard as the base plate and placing specimens or specimen holders on the reference standard or on three accurate support balls positioned across its surface.^[2]

The Logitech LG2 is used in the production of parallel specimens. The Logitech LG2 enables parallel faces to be prepared by bringing the polished face of the specimen into alignment with the plane of the optical reference standard and then polishing the second face in this plane. The Logitech LG2 can prepare specimens to parallelism better than 2 seconds of arc using this method. The Logitech LG2 can also generate angles of up to ±3 minutes of arc by placing an angled slip gauge on top of the optical reference standard and resetting the autocollimator.^[2][1]

Autocollimators in this class are used in precision optics and specimen preparation where angular control, parallelism, or deliberate wedge must be established on polished parts. Such instruments are relevant to laboratory and process environments that prepare optical components, technical materials, and other specimens requiring controlled surface orientation. The measurement task commonly supports prism work, flat sample preparation, and angular setup for subsequent finishing or inspection.