Labnic Ion Concentration Meter is a tabletop device for continuous fluoride ion measurement, with a range of minus 2 to 18 pH, 0 to 14 pX, and automatic temperature compensation from 0 to 100 degrees Celsius. It features a waterproof 6.5-inch LCD, an Omron touch panel and data storage. https://www.labnic.com/ion-concentration-meter/lbn-im191