Horiba Ltd provides analytical and measurement equipment. The automotive test systems segment contributes the largest percentage of revenue and supplies engine, driveline, brake, wind tunnel balance, and emissions test systems. The scientific segment sells instruments like pH meters, X-ray microscopes, and spectrometers. The semiconductor segment supplies mass flow controllers that are used in the semiconductor manufacturing process. The medical-diagnostic segment sells blood testing instruments and reagents for the in vitro diagnostics market. The process and environmental segment provides solutions associated with environmental regulations, such as air-pollution and water-quality analyzers. Horiba generates the largest proportion of its sales in Japan.