more pics. manufacturer was Precision Scientific, Chicago(defunct)http://files.engineering.com/getfile.aspx?folder=a55d4bbd-f1ac-4936-bd81-5a74162f6e4a&file=image3.JPG
We have discovered some sort of instrument in a closet here at our Environmental Division of Health Dept offices. Sanitarians and engineers here are stumped as to what it is. We believe it is 1970's vintage plus or minus a decade. Hoping I can upload photos. Would appreciate any comments, etc...