Rosemount Analytical Model 403 / 403VP Endurance Conductivity Sensor

The Rosemount Analytical Model 403 and 403VP Endurance Conductivity Sensors are intended primarily for the determination of electrolytic conductivity in water-for-injection (WFI). The sensors are also used in water purification systems in the food and beverage industry.

ENDURANCE Model 403 and 403VP sensors are contacting sensors. They are available in cell constants of 0.01, 0.1, 1.0, and 10/cm. The choice of cell constant depends on conductivity. High conductivity samples require larger cell constants.

Sensors with 0.01, 0.1, and 1.0/cm cell constants have concentric titanium electrodes separated by a PCTFE (Neoflon®) insulator. Ethylene propylene O-rings seal the internal parts of the sensor from the process liquid. The sanitary flange is 316 stainless steel. All wetted plastics and elastomers are compliant with 21CFR177, and all wetted surfaces have a 16 microinch (0.4 micrometer) Ra finish. The sensor is shipped with a certificate of conformance for materials and surface finish.

Electrolytic conductivity is a strong function of temperature, and conductivity readings are typically converted to the value at a reference temperature. A platinum RTD in the inner electrode measures the temperature.

Sensors with a 10/cm cell constant have side-by-side graphite electrodes and an epoxy body. The RTD is enclosed in a titanium thermowell protruding from the end of the sensor. Graphite electrode sensors are not compliant with 21CFR177, nor do they have a 16 microinch Ra surface finish.

ENDURANCE Model 403 and 403 VP sensors are available with either a 1-1/2 inch or 2-inch TriClamp® sanitary process connection.

Model 403VP has a Variopol 6 (VP) quick disconnect watertight connector. Wire the interconnecting cable to the analyzer and run the cable to the sensor. The sensor plugs into the cable receptacle. To replace the sensor, simply disconnect the Variopol fitting and plug in a new sensor. There is no need to rewire or rerun cable.