871A General purpose gel filled disposable pH/ORP sensor
The Foxboro® brand 871A Electrochemical Sensors, when used with 871A Accessories, are suitable for many process pH and ORP measurement applications. As symbolized by the “CE” marking, these Sensors conform to all applicable European Union directives.
These sensors are used with Foxboro 870ITPH Intelligent Transmitters, 875PH Intelligent Analyzers, 870PH Analog Transmitters, and 873PH and 873DPX Electrochemical Analyzers.
This innovative pH sensor assembly is suitable for many industrial pH applications. Its body is PVDF (polyvinylidene fluoride), a material which provides excellent resistance to chemicals. The flat glass (for pH), and platinum or gold (for ORP) measuring electrodes, in conjunction with the double-junction reference electrode, provide excellent performance within the specified operating range.
The 871A uses the Foxboro flat glass pH electrode. This electrode provides long life because of its rugged construction. In addition, its flat smooth surface resists coating and has a self-cleaning action in a flow stream.
Automatic temperature compensation (ATC), utilizing a platinum resistance temperature detector (RTD), is a built-in feature in the 871A Sensor.
features
- SENSOR DIAGNOSTICS
- When used with the Foxboro 870ITPH Intelligent Transmitter or 875PH Intelligent Analyzer, the intelligent configurations of the sensor (Model Code Signal Conditioning Codes -3 and -4) provide diagnostic information. Sensor health checks will reveal the following faults;
- • Broken glass electrode
- • Aging glass electrode
- • Liquid leakage into sensor body
- • Failure of high impedance preamplifier in sensor (Signal Conditioning Code -4 only)
- • Failure of temperature compensation element
- • Excessive coating of the reference electrode, or sensor not in contact with process water.
- INTRINSICALLY SAFE AND NONINCENDIVE DESIGN
- The 871A Sensors have been designed for use in intrinsically safe and hazardous area locations when used with the Foxboro Transmitters and Analyzers listed below:
- • Model 875PH Intelligent Electrochemical Analyzer
- • Model 870ITPH Intelligent Electrochemical Transmitter
- • Model 870PH Analog Output Transmitter
- • Model 873PH Electrochemical Analyzer
- • Model 873DPX Electrochemical Analyzer