These multi-parameter portable meters (photo) measure pH, conductivity, dissolved-oxygen and ion concentration. All three instruments are based on the rugged design of SevenGo, and are watertight according to IP67. The three new meters expand the range of portable instruments and offer innovative Intelligent Sensor Management. The SG23 is a robust, dual-channel pH/conductivity meter for routine work. The professional pH/ion/conductivity meter SG78 combines all functions of pH and conductivity measurement with a full-fledged ion mode. The multi-parameter SG68 covers the measures pH/ion/dissolved oxygen. Handy features like automatic air-pressure compensation, helpful ion mode, and a wireless infrared communication port, save time and guarantee correct results. — Mettler Toledo, Columbus, Ohio