pH Sensor InPro3250i/SG/120
High Performance, High Accuracy pH & ORP.The InPro 3250i SG/120 is a digital, pre-pressurized, low maintenance ISM pH & ORP sensor combined with a temperature sensor for in-line measurement in demanding applications. The 120 mm version is optimal for short installation lengths.
Highly Accurate in Extreme Conditions
The InPro 3250i SG/120 provides stable and precise readings under extreme process conditions from pH 0-14 thanks to its high-alkali pH glass membrane.
Low Maintenance and Easy-to-Use
This digital pH sensor has Intelligent Sensor Management (ISM) technology, offering predictive diagnostics to reduce maintenance and calibration.
Sterilizable and Autoclavable
This sensor provides fast and precise pH and ORP measurement, even after repeated autoclaving and sterilization cycles.

ISM (Digital) or Analog | ISM (Digital) |
pH Sensing Technology | Highly Alkali Resistant Glass Membrane for Tough Conditions (HA) |
pH Range | 0 – 14 |
Reference System | Pre-pressurized liquid electrolyte, ceramic diaphragm, Argenthal cartridge with silver-ion trap |
Operating Temperature (Celsius) | 0 °C - 100 °C |
Operating Temperature (Farenheit) | 32 °F - 212 °F |
Cable Connector | K8S |
Certificates & Approvals | CE; ATEX/IECEx: Ex ia IIC T6 / T5 / T4 / T3 Ga / Gb; EHEDG; FM: IS Cl. I, II, III, Div 1, GR ABCDEFG / T6; PED; METTLER TOLEDO Quality Certificate |
Measurement Parameter | pH; ORP/Redox |
Model Family | InPro3250(i) |
Operating Pressure (Bar) | 0 to 4 barg |
Operating Pressure (PSI) | 0 to 58 psig |
Process Connection | Pg 13.5 Thread |
Sensor Length | 120 mm |
Shaft Material | Glass |
Solution Ground/Redox Metal | Platinum |
Sterilizable/Autoclavable | Yes |
Temperature Sensor | Digital |
Hazardous Area Approvals | Yes |
Hygienic/Biocompatibility Approvals | Yes |
Primary Media/Application | Chemical Processes; Pharmaceutical/Life Science Production |
Refillable Electroyte | No |
Material Number(s) | 52005373 |
Reliable, Accurate and Robust
The InPro 3250i SG/120 is designed to withstand the rigors of your production. Its pre-pressurized, maintenance-free reference system ensures high reproducibility and reliable measurement performance under diverse operating conditions.

Advanced Sensor Diagnostics with ISM
This pH sensor features a digital signal and intelligent diagnostics to help manage your maintenance. The sensor provides a clear display of its remaining lifetime, time remaining until calibration, and counts of the SIP and CIP cycles it has undergone.

Easy Validation
The InPro 3250i SG/120 is suited for chemical and pharmaceutical production. Its certification covers hazardous zone use, biocompatibility of the electrolyte, and all relevant hygiene and safety regulations.

Versatile to Meet Your Application Needs
This sensor can measure both pH and ORP (Redox), and has a built-in digital temperature sensor. It is pressure resistant up to 4 barg (58 psig), has a watertight connector, and can withstand repeated sterilization and autoclave cycles.

Documentation
Accessories
Sensor Calibration & Maintenance Tools

Material No.: 30130614

Material No.: 30283620

Material No.: 52300383

Material No.: 30126791
Material No.: 30130631
Sensor Simulation & Validation
Material No.: 52300410