Foxboro 875CR Conductivity / Resistivity Transmitter

875CR Line-Powered Analyzer

The Foxboro 875CR is a high-performance, microprocessor-based intelligent electrochemical analyzer specifically designed for measuring contacting conductivity and resistivity in a wide variety of liquid-phase process applications. Built for demanding industrial environments, the 875CR offers superior accuracy, reliability, and flexibility, making it a trusted solution for critical applications in water treatment, chemical processing, power generation, and pharmaceutical production. Unlike loop-powered field transmitters (e.g., the 876CR), the 875CR is line-powered, allowing it to drive two independent 4–20 mA analog outputs, support optional HART® digital communication, and provide enhanced functionality like dual alarm relays, remote configuration, and a large high-resolution LCD display. These capabilities make the 875CR especially well-suited for control room or panel-mounted analytical measurement systems, where detailed feedback, control logic, and robust user interfaces are required. The analyzer is compatible with Foxboro 871CR and 871CC contacting conductivity/resistivity sensors, offering precise measurements across a wide conductivity/resistivity range—from ultrapure water resistivity monitoring (up to 20 MΩ·cm) to high-concentration chemical process streams. It also supports temperature compensation using built-in temperature elements in the sensors, ensuring accurate readings in rapidly changing process environments. The 875CR’s menu-driven interface and keypad navigation provide intuitive, localized access for configuration, calibration, and real-time diagnostics, while the RS-232 port allows remote configuration using PC-based tools. Its two fully isolated analog outputs can be independently assigned to any measured or calculated variable, enabling flexible control strategies. Additionally, the unit includes data logging, history tracking, and custom alarm settings, making it valuable for audit compliance and maintenance scheduling. Rugged and reliable, the 875CR is available in panel, surface, or pipe-mount enclosures that meet NEMA 4X / IP65 standards for dust and water resistance. It is also certified for use in hazardous areas (FM, CSA, IECEx, ATEX), making it suitable for installations in chemical plants, refineries, and explosive gas zones.

Ideal for:

High-Purity Systems
Chemical and Petrochemical
Water/ Wastewater
Power
Food and Beverage
Pharmaceutical
Batch Processing
Multipurpose Systems

Features:

Compatible with Foxboro 871CR and 871CC sensors
Auto compensation for temperature changes
Supports internal and external sensors
Dual 4-20 mA outputs
Optional HART digital communication
Two form C relays
240 × 128-pixel backlit display
4-button keypad
RS-232 serial port
Smart diagnostics
Stores key events and errors
Supports audit compliance
Two user-defined profiles
Flexible mounting:
- Panel-mount
- Surface-mount
- 2-inch pipe mount
NEMA 4X / IP65 rated
Indoor/ outdoor
Certifications
- FM, CSA, ATEX, and IECEx
- Class I, II, III Division 2
- Zone 2 environments