Senz-Tx-Oxygen-Transmitter

Supported Applications

The Ntron SenzTx is a compact oxygen transmitter designed to monitor oxygen (O₂) concentration in gas samples. The series utilizes two distinct measurement technologies: electrochemical cells and zirconia semiconductor sensors. It functions as part of a control system, such as a PLC, or operates as a standalone measuring unit for industrial process applications.

The transmitter is engineered to measure oxygen content within specified parts-per-million (ppm) or percentage (%) ranges. The series supports measurement in background gases containing hydrocarbons when configured with the electrochemical sensor option.

Operating Conditions & Performance

Performance specifications vary by sensor technology and selected range:

• Measurement Ranges: 0...1000 ppmv; 0...1%, 0...25%, 0...96%, or 0...100% (Zirconia); 0...1000 ppmv, 0...1%, or 0...25% (Electrochemical).
• Accuracy: Ranges from +/- 0.5 ppm at the 10 ppm range to +/- 1% @ 95% for Zirconia sensors; Electrochemical accuracy follows similar tiered specifications per the Accuracy Table.
• Response Time (T₉₀): < 15 seconds @ +25 °C (+77 °F) within selected range for both sensor types. Note: Short-form manuals cite longer response times (<180s from 21% to 1000ppm O₂) which may reflect specific operational conditions or older configurations.
• Operating Temperature: -25...+60 °C (-13...+140 °F) for Zirconia; 0...+45 °C (+32...+113 °F) for Electrochemical sensors.
• Pressure Range: 900...1100 mBarabs (Differential pressure between analyzer and electronics max. =100 mbar).
• Ingress Protection: IP66 rating with a chromated aluminum housing.

Configuration Options

The SenzTx series offers configurable options for process connection, output signals, and sensor life expectancy to suit specific installation requirements.

• Sensor Technology:
  • Zirconia (ZR): Semiconductor measuring cell with a typical service life of up to 5 years. Features low drift and fast response times.
  • Electrochemical (EC): Depleting element sensor suitable for hydrocarbon-containing gases, with an expected life of up to 18 months under normal conditions.
• Process Connections: Flow-through base (typically G 1/8" or 1/8" NPT) and KF40 flange options are available. The modular design supports custom labeling.
• Output Signals: Analog outputs include 4...20 mA or 0-10V DC depending on the specific model configuration. Digital communication is provided via RS485 Modbus (A/B).
• Power Supply: Operates on 24 VDC ±10% to ±15%, with a maximum consumption of 50mA or 4.8W.
• Cable Lengths: Supplied standard at 1 meter, with options for 3 meters and 10 meters available.

Key Product Differences

The series distinguishes between Zirconia (ZR) and Electrochemical (EC) configurations based on sensor chemistry, life expectancy, and environmental tolerances. Mechanical dimensions vary by the combination of sensor type and process connection:

• ZR Flow-through: Overall length 156.2 mm; Weight 344 g.
• EC Flow-through: Overall length 163.2 mm; Weight 391 g.
• KF40 Flange Options: Zirconia KF40 units measure 198.2 mm in overall length (Weight: 350 g), while Electrochemical KF40 units are also available with corresponding dimensional variations.

The series includes a marine-approved version meeting Lloyd's Register EN 60945 standards, alongside ETL UL-61010-1 and EMC EN 50270 certifications. Calibration intervals differ by sensor type: Zirconia sensors typically require annual checks (12 months), whereas Electrochemical cells may need calibration every 3 to 6 months.