The OT‑4XX Series Oxygen Transmitter, developed by EMS Kontrol, is designed for precise, continuous monitoring of oxygen concentration in industrial, laboratory, and HVAC environments. With its rugged IP67 housing and long-lasting sensor, the OT‑4XX delivers reliable O2 measurement to support safety, process control, and air quality applications.

Function and Output Options
The OT‑4XX transmitter measures ambient or duct oxygen levels and converts the readings into standard industrial output formats. Depending on the model, you can choose between:

OT 401: Analog 0–10 V output

OT 441: Analog 4–20 mA output

OT 461: Digital RS‑485 Modbus RTU output

These options ensure seamless integration with Building Management Systems (BMS), PLC controllers, and SCADA systems in both new and existing installations.

Measurement Range and Accuracy
The OT‑4XX provides oxygen concentration measurements ranging from 0–25% VOL, with a sensitivity of ±0.1 % VOL and accuracy of ±1 % VOL. This level of precision makes it suitable for monitoring oxygen levels in ventilation systems, inert gas environments, fermentation control, and medical or laboratory applications where accurate O2 tracking is critical. 

Construction and Installation
The device is housed in a robust IP67-rated plastic enclosure (excluding the sensor), offering excellent protection against dust and moisture. The O2 sensor module is easily replaceable, supporting quick maintenance and long-term reliability. Installation is simplified through a wall-mountable design with standard screw terminals and user-friendly assembly procedures, making it ideal for critical process and safety monitoring applications. 

OT‑401 Oxygen Transmitter With Display – Technical Features

- Power Input: 12–24 V DC

- Output Signals: 0–10 V

- Measurement Range: 0–25 % VOL O2

- Sensitivity: ±0.1 % VOL

- Accuracy: ±1 % VOL

- Sensor Life: 2 years

- Protection Class: IP67 (excluding sensor)