InPro 4850i/120 pH Sensor for Chlor-Alkali Applications

pH Sensor InPro4850i/SG/120

For Tough Chlor-alkali Processes.The InPro 4850i/120 is a dual-membrane pH and ORP sensor for measuring processes with a stable sodium concentration. This 120 mm probe combines accurate measurement with durability for tough environments.

For use in chlor-alkali production

The InPro 4850i is specifically designed for chlor-alkali processes. It uses the sodium concentration in the process (brine) as a reference.

Designed to withstand harsh conditions

This pH sensor has no diaphragm, making it immune to chlorine and other oxidizing agents that can lead to failure in other pH and ORP electrodes.

An advanced digital pH sensor with ISM

The InPro 4850i has an ISM digital signal that is immune to interference and distortion and ensures 100% signal integrity and stability.

pH Sensor InPro 4850i/120
Specifications - pH Sensor InPro4850i/SG/120
ISM (Digital) or Analog
ISM (Digital)
pH Sensing Technology
Highly Alkali Resistant Glass Membrane for Tough Conditions (HA)
pH Range
0 – 14
Reference System
Hermetically sealed, sodium sensitive glass membrane
Operating Temperature (Celsius)
-10 °C - 120 °C
Operating Temperature (Fahrenheit)
14 °F - 248 °F
Cable Connector
Certificates & Approvals
CE; ATEX/IECEx: Ex ia IIC T6 / T5 / T4 / T3 Ga / Gb; FM: IS Cl. I, II, III, Div 1, GR ABCDEFG / T6; PED; METTLER TOLEDO Quality Certificate
Measurement Parameter
pH; ORP/Redox
Model Family
Operating Pressure (Bar)
0 to 12 barg @ 120 °C
Operating Pressure (PSI)
0 to 174 psig @ 248 °F
Process Connection
Pg 13.5 Thread
Sensor Length
120 mm
Shaft Material
Solution Ground/Redox Metal
Temperature Sensor
Hazardous Area Approvals
Hygienic/Biocompatibility Approvals
Primary Media/Application
Chemical Processes
Refillable Electroyte
Material Number(s)

Long life in chlor-alkali applications

The InPro 4850i/120 features a sodium-sensitive glass membrane that uses the chlor-alkali process brine as a reference. The reference system has no junction, which allows the pH sensor to resist oxidation and extends the sensor's life.

Versatile pH and ORP sensor

This combined pH and ORP sensor uses a platinum solution ground and shielding system that stabilizes the signal and enables redox measurement. Additionally, the digital signal provides 100% signal integrity for stable and accurate measurement.

Diagnostics to reduce maintenance

The ISM predictive diagnostics on the InPro 4850i allow the shift from time-based maintenance to predictive maintenance. The sensor provides a clear indication of when it will need to be calibrated and replaced to reduce unplanned downtime.

Compliance with safety regulations

The InPro 4850i chlor-alkali pH and ORP sensor is Ex-certified, so it can be used for demanding processes in the hazardous-classified zones of your production facility.


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pH Sensor InPro4850i/SG/120
Hazardous Area
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