The waterproof, handheld Extech FL700 fluoride meter utilizes a rugged flat surface fluoride electrode with built-in temperature compensation. The measurement technology is EPA Method 340.2 compliant (potentiometric ion selective electrode) and has a fast response time (< 1 min). The handheld Extech FL700 fluoride meter and tester is easy to use for either field or lab testing and its memory can store up to 25 labeled readings.