Armin Elmendorf, a mechanical engineer working for Thwing-Albert Instrument Co. in West Berlin, N.J., invented a machine in 1921 that would test the tearing strength of paper. Ninety years later, Thwing-Albert celebrates the development of the Elmendorf Tear Tester into a worldwide standard for measuring tear-resistance of paper, textiles, roofing products, film, foils and more. The newest grandchild of the Elmendorf Tear Tester is the ProTear, offering several capacity configurations from 200 to 25,600 grams that can be changed quickly with augmenting weights. This eliminates the need for multiple pendulums and simplifies the testing of different materials. The company manufactures three models: electronic, mechanical and heavy duty.