The Ohaus Starter ST400D-G is a high-performance, low-maintenance dissolved oxygen (DO) meter equipped with optical methodology for accuracy. It is designed for both field and lab dissolved oxygen measurement. The meter features a backlit color liquid crystal display (LCD) for easy reading and operation. It is powered by 4 AAA batteries and has a battery life of 12 hours. The ST400D-G has a measurement range of 0.00 – 20.0 mg/L (ppm) and a measurement resolution of 0.01 mg/L. It offers automatic temperature compensation and manual salinity compensation. The meter comes with an STDO21 electrode and has a net weight of 0.35 lb.