YSI Inc.

Yellow Springs Instruments Company (now YSI Inc.) began operations as a four-person company in 1948 that produced sensors and related medical instruments. In 1983, the company was converted to employee ownership. Today, the company has roughly 250 employee-owners and its primary business involves the manufacture of water quality and environmental monitoring applications. YSI actively pursues a “triple bottom line” of business, social, and environmental performance and tracks its progress with an annual sustainability report.