The AquaMetrix Model ES-5 Series are loop-powered toroidal (electrodeless) conductivity sensors designed for processes where conventional contacting sensors may become fouled or corroded . These probes are unique in the marketplace, providing direct 4-20mA output without requiring a separate transmitter .

Each sensor comes standard with a built-in Pt100 RTD temperature device, providing automatic temperature compensation to 77°F (25°C) . The ES-5 Series are equipped with 1.5" MNPT threads on both ends, enabling either in-flow pipeline installation or submersion mounting in tanks and open vessels .

The sensor operates on the toroidal principle: two wire-wound toroids encapsulated in a plastic body act as transmitter and receiver. An electric current induced between the toroids through the process solution is directly proportional to conductivity .

Three measurement ranges are available: 0-10 mS/cm, 0-100 mS/cm, and 0-1000 mS/cm . Maximum flow rate is 10 ft/s (3 m/s) . The CPVC outer shell withstands operating temperatures from 14 to 140°F (-10 to 60°C) .

Key advantages include no electrode corrosion (toroid fully encapsulated), low maintenance with reduced cleaning requirements, and single wetted material for easier chemical compatibility . Applications include plating, high purity water, pharmaceuticals, reverse osmosis, fume scrubbers, boilers, cooling towers, textile manufacturing, and food and beverage processing .