Profile: J&L Metrology Inc. manufactures optical comparators. Our products are optical comparator bulbs, optical comparator charts, optical comparator digital readouts, optical comparator fixtures, glass master inspection kits and glass hand held scales. Our brands are J & L Metrology™ and Vermont Precision™. Our glass charts are used to achieve dimensional stability, as well as the ability to diffuse the light through a matte or frosted finish on the glass. Our glass master inspection kits are used to determine lens magnification, table measuring accuracy and axis orthogonality.