I talked to my bus partner, and he said it's an old optical RF that works like a survey tool. He said there should be a dial on it and an optic and you are supposed to get certain angles from points and then do real math to get a range. Once LRFs came out, these disappeared. It looks like you have the instructions...I'd keep it all together. They sell on ebay for between $20-$40.
I looked them up and they are actually all over; used by the forest service, BLM (not the commies), etc. Probably surveyors too.
https://www.fs.fed.us/eng/pubs/html/98241307/98241307.htmlFrom the above website:
"Optical
Optical distance-measuring devices typically use the coincidence method of determining distance; which uses a series of lenses and mirrors to produce a double image. The double images on mirrors are brought together by rotating a dial until both images merge into one. The dial has a distance indicator. When the two images merge, the distance to the target is read directly off the dial."
I looked them up and they are actually all over; used by the forest service, BLM (not the commies), etc. Probably surveyors too.
https://www.fs.fed.us/eng/pubs/html/98241307/98241307.htmlFrom the above website:
"Optical
Optical distance-measuring devices typically use the coincidence method of determining distance; which uses a series of lenses and mirrors to produce a double image. The double images on mirrors are brought together by rotating a dial until both images merge into one. The dial has a distance indicator. When the two images merge, the distance to the target is read directly off the dial."
That is a cool old tool!
