The TD-4100 XD is a ruggedised, continuous online fluorescence-based oil-in-water monitor. The XD is designed specifically for offshore/onshore oil production, refining, petrochemical, mining, and other industries that require robust online hardware for severe duty and hazardous area locations. The monitor is skid-mounted and constructed of 316 stainless steel, including an external keypad for operation in corrosive environments.

The TD-4100 XD detects and measures crude oil, refined fuels, fuel oils, lubricating or hydraulic fluids, as well as aromatic solvents in water. Detection limits range from low ppb (μg/L) to high ppm (mg/L).