Product imagery shown for reference. Confirm the exact configuration before ordering.
AST-40D %O2 sensor Replaces Analox 9100-9220-9B for O2EII and O2EII Pro Analyzers
AST-40D % O2 sensor Replacement to Analox 9100-9220-9B O2 sensor for O2EII and O2EII Pro analyzers. AST-40D % O2 sensor is the perfect choice offered as a drop-in replacement by Applied Sensing Technologies. This sensor is a form-fit-function of O2 sensor in Analox O2EII O2EII Pro analyzers. Sensor…
Technical information
Product details
Technical overview
AST-40D % O2 sensor Replacement to Analox 9100-9220-9B O2 sensor for O2EII and O2EII Pro analyzers. AST-40D % O2 sensor is the perfect choice offered as a drop-in replacement by Applied Sensing Technologies. This sensor is a form-fit-function of O2 sensor in Analox O2EII O2EII Pro analyzers. Sensor can measures oxygen in any range between 0-100% in a variety of gas streams. A fresh sensor usually provides with 44-90 uA current in air. Sensor has a special connector. The external sensor casing is with M16x1 thread. Expected sensor life is 36 months in air at ambient temperature and pressure. Proprietary electrolyte formulation and anode structure of AST sensors ensure full utilization of Pb anode thus ensuring longer sensor life without any significant signal drift thus minimizing periodic calibration requirement. AST brand sensors are designed and manufactured in the USA.
Applications and guidance
Advanced Sensor Technology
AST-40D % O₂ Sensor – Replacement for Analox O2EII / O2EII Pro
The AST-40D % O2 Sensor from Applied Sensing Technologies serves as a direct replacement for the Analox 9100-9220-9B oxygen sensor used in Analox O2EII Analyzer and Analox O2EII Pro Analyzer instruments.
This sensor provides a form-fit-function drop-in replacement, which allows users to install it directly into compatible analyzers without modifications. As a result, it offers a convenient and cost-effective solution for maintaining oxygen monitoring equipment.
The AST-40D % O2 Sensor measures oxygen concentrations from 0 to 100% across a wide variety of gas streams. In addition, a fresh sensor typically produces an output current between 44 and 90 µA in air, which ensures reliable analyzer performance.
The sensor features a special electrical connector and an external casing with an M16 × 1 threaded body, which allows secure installation in the analyzer.
Moreover, the sensor incorporates a proprietary electrolyte formulation and optimized anode structure. This design ensures full utilization of the lead (Pb) anode, which helps extend sensor life. Consequently, the sensor provides long operating life with minimal signal drift, reducing the need for frequent calibration.
Under ambient temperature and pressure in air, the expected operating life of the sensor is approximately 36 months.
Finally, AST brand oxygen sensors are designed and manufactured in the United States by Applied Sensing Technologies, ensuring dependable quality and performance.
AST Model SRX-40D Replaces
- Analox 9100-9220-9B
- Fits in Analox O2EII and O2E2II PRO Analyzers
Specifications and compatibility references
Application support
Not sure this is the right sensor?
Send the existing sensor or analyzer model and AST will help confirm the correct replacement.




