Electronic instruments maker Ametek (Paoli, PA) has bought Chicago-based weathering test instruments firm Atlas Material Testing Technology from private equity firm Industrial Growth Partners for nearly $159 M in cash. The acquisition will help Ametek grow its business in the materials testing equipment market and expand its presence in the rapidly growing photovoltaic testing market, the company said.

Atlas will become part of the Ametek Measurement & Calibration Technologies division, which develops material test instruments with engineering activities in the United States, Denmark and the United Kingdom. Atlas offers its products and services to laboratories and aerospace, paint, coating, polymer, plastic, solar, pharmaceutical, LED and automotive producers. It has production activities in Germany and a network of outdoor and laboratory testing locations worldwide. Atlas is seen to record sales of nearly $85 M in 2011.