PTL Originated in 1977 as the Inorganic Precious Metals division of Princeton Testing Laboratory, with Ronald McCloskey as manager. Changes at the corporate level in August 1987 resulted in PTL becoming a separate corporation which Ronald McCloskey purchased in April of 1988. PTL testing laboratory provides testing in all of the following categories: Physical and Non-Destructive, Catalyst, Weld Inspection, Inorganic and Precious Metals, Sampling and Representation, Emission, Spectroscopy, Fuels, Trace Metals, Tin/Lead Solder, And a score of Miscellaneous Testing.