Overview
The Rosemount 400-12 is a contacting conductivity sensor engineered for precise measurement in industrial process monitoring and control applications. This screw-in sensor delivers factory-measured accuracy with no initial calibration requirements, making it ideal for water quality monitoring, chemical processing, power generation, and wastewater treatment systems.
Key Features
- Screw-in design with Variopol quick disconnect fitting for fast installation
- Cell constant of 0.1/cm for optimal range and sensitivity
- Pt-1000 temperature compensation for accurate readings across operating range
- Factory-measured cell constant ensures out-of-the-box accuracy
- Cable termination for easy integration into existing systems
- Designed for non-corrosive liquid environments
Technical Specifications
- Maximum Temperature: 221°F (150°C)
- Maximum Pressure: 250 PSIG (1725 KPA)
- Cell Constant: 0.1/cm
- Temperature Compensation: Pt-1000
- Conductivity Range: 0–20,000 µS/cm
- Connection Type: Variopol quick disconnect fitting
- Standard Cable Length: 10 feet
- Mounting: Screw-in general purpose design
Typical Applications
- Water and wastewater treatment facilities
- Chemical process monitoring and control
- Power plant condensate and feedwater applications
- Pharmaceutical manufacturing and quality assurance
- Food and beverage production
- Cooling tower water quality management
- Boiler water conductivity measurement
Compatibility & Replacements
Compatible With
- Rosemount transmitter models 56, 1056, 1057, 1066, 5081
- Legacy transmitter models 1055, 54C, 54eC, 4081C, 6081-C, XMT-C
- Standard industrial control and monitoring systems
- Systems requiring 0.1/cm cell constant sensors
Replaces / Drop-In Replacement For
- Rosemount 400-12-36 (extended insertion length variant)
- Equivalent 0.1/cm cell constant conductivity sensors in legacy systems
Works With
- Rosemount Analytical measurement platforms
- Pt-1000 temperature compensation compatible systems
- Standard 4–20 mA analog control loops
- Industrial instrumentation and SCADA networks


























