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Vintage Keuffel & Esser Co. Model#: 71 4030 "Straightness of Line of Sight Collimator" w/ Original Wooden Latching CaseFor sale is a vintage 1961 Keuffel & Esser Co. "Straightness of Line of Sight Collimator" Model#: 71 4030 in it's original wooden case.I'm a land surveyor and I stumbled across this on facebook marketplace while I was looking for some used equipment in St. Louis. I purchased it from a company called "AVMATS". It appears to have been used by the United States Air Force, and has a sticker on it inscribed "USAF CALIBRATION SYSTEM" "BASE REFERENCE STANDARD". It appears to have been calibrated in 1982.The K&E catalog has this to say about it:
"This instrument is used in testing and adjusting all optical metrological and surveying instruments. It checks the straightness of the line of sight of any sighting telescope from minimum focus to 100ft. The collimator contains 7 reticules positioned to simulate distances of 0, 4, 10, 25, 50, 100ft., and infinity."This instrument seems to be in good condition, but it appears to have been painted green by the air force. This green paint is tacky (sticky) and failing. When I was trying to clean it with a mild cleaner the paint was rubbing off with the dust. The original black color still resides beneath and seems to be in good shape from the areas that I began to uncover. I have not used it or tested it, and I am selling it as-is.
