OxyScout Ultra-Trace and OxyScout Trace are optical oxygen analyzers for continuous ppm-level O₂ measurement in natural gas. Ultra-Trace covers 0–50 ppm* for low-ppm specifications, and Trace covers 0–1,000 ppm*. Neither model has an electrochemical cell to replace.
A trace oxygen analyzer measures oxygen in parts per million (ppm) by volume. Ambient air is about 20.9% oxygen, or 209,000 ppm, so a small leak of air into a sample line or process stream shows up quickly at ppm levels. OxyScout trace models measure with a fully optical sensor and send the reading over 4–20 mA and RS-485 Modbus RTU at the same time.
| Model | Measuring range* | Detection limit* | Accuracy* | Typical application |
|---|---|---|---|---|
| OxyScout Ultra-Trace | 0–50 ppm O₂ | ≤0.5 ppm O₂ | ±2 ppm or ±5% of reading, whichever is greater | Sales gas, custody transfer and vapor recovery units with a low-ppm specification |
| OxyScout Trace | 0–1,000 ppm O₂ | 50 ppm O₂ | Typically ±2% of reading or ±0.01% O₂ (100 ppm), whichever is greater | Gathering, vapor recovery units and process |
*Based on controlled lab conditions.
Choose a range that puts your oxygen limit well inside the scale, with enough headroom above the limit to see an upset rather than a pegged signal. OxyScout Trace has a 50 ppm detection limit*, so a low-ppm specification calls for OxyScout Ultra-Trace. The pipeline oxygen limits guide matches published limits to each range.
OxyScout Ultra-Trace is the low-ppm model, with a 0–50 ppm O₂ range* and a detection limit of ≤0.5 ppm O₂*.
| Measuring range* | 0–50 ppm O₂ |
|---|---|
| Detection limit* | ≤0.5 ppm O₂ |
| Accuracy* | ±2 ppm or ±5% of reading, whichever is greater |
| Typical application | Sales gas, custody transfer and vapor recovery units with a low-ppm specification |
*Based on controlled lab conditions.
OxyScout Trace covers 0–1,000 ppm O₂* with a 50 ppm O₂ detection limit*.
| Measuring range* | 0–1,000 ppm O₂ |
|---|---|
| Detection limit* | 50 ppm O₂ |
| Accuracy* | Typically ±2% of reading or ±0.01% O₂ (100 ppm), whichever is greater |
| Typical application | Gathering, vapor recovery units and process |
*Based on controlled lab conditions.
Both trace models share the installation, wiring, firmware and communications of the full OxyScout line. The full specification table also covers options and accessories.
| Measurement | The analyzer uses a fully optical O₂ sensor, so there are no electrochemical cells to replace. |
|---|---|
| Outputs | The outputs are a 4–20 mA loop (current sink) and RS-485 Modbus RTU (2-wire half-duplex). |
| Power | The analyzer runs on 9–36 VDC and draws 35 mA plus the current used by its analog outputs. |
| Process / ambient temperature | Process and ambient temperature is 0 to 50 °C, and storage temperature is −20 to 70 °C. |
| Pressure | Up to 250 PSI input pressure† |
| Humidity / flow | The analyzer is specified for non-condensing conditions, and it has no flow restrictions. |
| Area classification | The analyzer is engineered for Class 1 Division 2 (Zone 2) hazardous areas. |
| Size / weight | The enclosure is 9 in high, 7 in wide and 2.5 in deep, and the analyzer weighs 4 lb. |
| Process connection | The process connection is 1/8 in tube compression. |
| Response time* | Typical response time is under 10 seconds. |
*Based on controlled lab conditions. Standard Sensors Corporation reserves the right to make revisions and/or changes without notice.
†Without Flowmeter installed. Higher ratings if regulator installed upstream.
Most high readings at ppm levels come from air entering the sample system, not from the analyzer. Oxygen moves inward through any imperfect fitting against line pressure, because each gas moves according to its own partial pressure.
The ZeroLeak™ Cell Block on every OxyScout is machined from one solid block, so minimal fittings are required inside the analyzer. Read more about the ZeroLeak™ Cell Block.
OxyScout Ultra-Trace has a detection limit of ≤0.5 ppm O₂.* OxyScout Trace has a detection limit of 50 ppm O₂*, so Ultra-Trace is the model for a low-ppm specification. *Based on controlled lab conditions.
Air trapped in tubing, fittings and regulators bleeds slowly into the flowing sample. On a fresh installation, expect the reading to fall steadily for several hours, and longer on long or complex sample runs, before it reaches a stable low-ppm value.
OxyScout has no cross-sensitivity or poisoning from H₂S, CO₂ or the other gases that plague galvanic cells.
Book a free 30-minute online meeting to review your application, range and quantities, then we send a quote. You can also call (936) 259-4643 or email [email protected].
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