Boston, MA 1/19/12 Keystone Tower Systems CTO Eric Smith (cq) demonstrates the use of the company's laser scanner in a spiral-welded pipe, on Thursday, January 19, 2012. Studying the mechanical properties of pipes to make sure they're structurally sound will aid in the development of new manufacturing techniques for wind turbine towers. Keystone is one of the companies using incubator space in Greentown Labs, which is located in Boston's Innovation District. (Pat Greenhouse/Globe Staff); Reporter: Michael Farrell; Section: Business; Slug: 23district