The term METAL TESTER can be summarized as an ASSAYER, which is a seven-letter word. An ASSAYER is someone who tests and evaluates the quality and composition of metals. They use a variety of methods to analyze the metal, such as spectroscopy, X-ray fluorescence, and chemical analysis. Assayers are often employed in the mining industry to ensure that the metals being mined meet certain standards. They also work in laboratories to test the purity of metals used in manufacturing.