Optical oxygen analyzer mounted on process piping in a natural gas facility

Reliable Oxygen Analyzers

OxyScout is an optical O2 analyzer that measures oxygen levels continuously in natural gas applications.

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No electrochemical
cells to replace
No cross-sensitivity
or poisoning
Low cost of
ownership
Natural gas applications

Oxygen analyzer applications for oil & gas

01

Vapor Recovery Units (VRU)

Tank vapor is pulled near atmospheric pressure, so air can leak in unseen. The analyzer reads that vapor before the VRU compressor.

The analyzer mounts on the vapor line between the separator and the VRU compressor.
Read the application page
02

Gas Compressor Stations

Worn rod packing and shaft seals can pull air in at low suction. The analyzer reads what the station delivers on the discharge line.

The analyzer mounts on the compressor discharge line.
Read the application page
03

Wellhead and Production

Oxygen is still undiluted at the wellhead and traceable to one well. The analyzer helps you find the source before it blends into the gathering line.

The analyzer samples at the wellhead or the production separator gas outlet.
Read the application page
04

Custody Transfer

The pipeline's oxygen limit is enforced here, and upstream air shows up as one number. The analyzer lets you watch that total at the fence line.

The analyzer mounts at the fence line.
Read the application page
More applications:Gas gathering linesTank blanketingFlare gas
Illustration of an OxyScout analyzer on strut channel beside a compressor skid, with a sample line into its cell block
Why optical

Why use an optical oxygen analyzer for natural gas?

Electrochemical cells are consumed as they measure, and gas conditions can shorten their life. An optical sensor takes the cell out of the measurement.

1

No electrochemical cells to replace

The recurring part of a typical O₂ analyzer is the electrochemical cell, and OxyScout has no cell to replace.

2

No cross-sensitivity or poisoning

OxyScout has no cross-sensitivity or poisoning from H₂S, CO₂ or the other gases that plague galvanic cells.

3

Minimal sample conditioning

The analyzer uses a ZeroLeak™ Cell Block, and an optional sample system is available when your stream needs one.

4

Trace to percent

The Ultra-Trace and Trace ppm ranges detect air ingress, and the percent ranges go up to 0–21 %, all from the same analyzer family.

5

Built for the field

The analyzer has an IP67 enclosure, works at 0 to 50 °C, runs on 9–36 VDC, and offers extreme-heat and extreme-cold enclosure options.

6

Engineered for hazardous areas

The analyzer is engineered for Class 1 Division 2 (Zone 2) hazardous areas.

Optical vs electrochemical

Why choose OxyScout over an electrochemical O₂ analyzer?

The initial purchase price of OxyScout is similar to an electrochemical O2 analyzer, but its total cost of ownership over 2-3 years is much lower. The optical sensor doesn't need the consumable cell replacement, so there are no cells to replace.

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Illustration of an OxyScout analyzer bolted to strut channel, sampling from a white natural gas pipeline

OxyScout at a glance

  • Typical total cost of ownership over 2-3 years is lower than an electrochemical O2 analyzer.
  • No electrochemical cells to replace
  • Response time under 10 seconds*
  • Up to 250 PSI input pressure†
  • Engineered for Class 1 Division 2 (Zone 2) hazardous areas

*Based on controlled lab conditions.

†Without Flowmeter installed. Higher ratings if regulator installed upstream.

Cost of ownership

How does optical compare with an electrochemical analyzer?

The purchase price is only part of what an oxygen analyzer costs over 2-3 years, because replacement cells, calibration visits and the drive to a remote pad all add to it. The initial purchase price of OxyScout is similar to an electrochemical O2 analyzer, but its total cost of ownership (TCO) over 2-3 years is much lower, as the table below shows.

Electrochemical (galvanic) cellOxyScout optical
Cost over 2-3 yearsReplacement cells add a recurring cost.The total cost of ownership is much lower, because no cells need to be replaced.
What wears outThe cell itself wears out and is replaced on a schedule.No electrochemical cell has to be replaced.
H₂S, CO₂ and other gasesThese gases can affect the cell.OxyScout has no cross-sensitivity or poisoning.
Sample conditioningThe need varies by model.Conditioning is minimal, and a sample system and enclosures are optional.
OutputsThe outputs vary by model.The outputs are 4–20 mA and RS-485 Modbus RTU.

Read the full optical vs electrochemical comparison

How it works

How does the analyzer connect to my process and system?

Illustration of gas sampled from a pipeline through a probe into OxyScout, then vented
STEP 1

Sample the stream

A small sample tap connects at 1/8 in tube compression, and a flowmeter and a sample system are optional.

STEP 2

Measure optically

A fully optical sensor reads oxygen continuously, and nothing in the measurement is an electrochemical cell.

STEP 3

Read it in your system

The 4–20 mA loop (current sink) and RS-485 Modbus RTU outputs feed your RTU, PLC or SCADA.

The optional sample system adds a pressure regulator and gauge, a secondary filter and a 3-way valve for calibration gas or process sample. A flowmeter to regulate vent flow to atmosphere, if required, and an extreme-heat or extreme-cold enclosure are also available.

Specifications

What are the OxyScout specifications?

RangesThe Ultra-Trace range is 0–50 ppm, Trace range is 0–1000 ppm and the Percent ranges are 0–1 %, 0–10 % and 0–21 % by volume.
Response time*Typical response time is under 10 seconds.
OutputsThe outputs are a 4–20 mA loop (current sink) and RS-485 Modbus RTU (2-wire half-duplex).
PowerThe analyzer runs on 9–36 VDC and draws 35 mA plus the current used by its analog outputs.
PressureUp to 250 PSI input pressure†
Area classificationThe analyzer is engineered for Class 1 Division 2 (Zone 2) hazardous areas, and the IP67 enclosure protects against dust and water.
Process connectionThe process connection is 1/8 in tube compression.

*Based on controlled lab conditions.

†Without Flowmeter installed. Higher ratings if regulator installed upstream.

See the full specifications on the product page

FAQ

Optical oxygen analyzers for natural gas: common questions

What is an optical oxygen analyzer for natural gas?

An optical oxygen analyzer measures O₂ with a fully optical sensor instead of an electrochemical (galvanic) cell. OxyScout, from Standard Sensors, measures trace (0–50 ppm, 0–1000 ppm) and percent (0–1 %, 0–10 %, 0–21 % by volume) oxygen continuously in natural gas, with no electrochemical cells to replace.

Why measure oxygen in natural gas?

Produced gas leaves the reservoir essentially free of oxygen, so any O₂ in the stream is air that got in at the surface: through tank thief hatches and VRU equipment, compressor rod packing and shaft seals, wellheads running at or below atmospheric pressure, or gathering-line fittings. Oxygen accelerates corrosion, can form a combustible mixture, and can put gas out of spec with a pipeline.

Where should the analyzer be installed?

Put it where air enters or where the spec is enforced. Typical locations are the vapor line between the separator and the VRU compressor, the compressor discharge line, the wellhead or production sample point, and the fence line at custody transfer. Using several points lets you trace a high reading downstream back to its source.

How is it different from an electrochemical oxygen analyzer?

An electrochemical (galvanic) cell is consumed as it measures and has to be replaced, and it can be affected by H₂S, CO₂ and other gases. OxyScout has no electrochemical cell to replace and no cross-sensitivity or poisoning from H₂S, CO₂ or the other gases that plague galvanic cells.

What ranges, outputs and power does it use?

The ranges are 0–50 ppm and 0–1000 ppm by volume (Ultra-Trace and Trace), and 0–1 %, 0–10 % and 0–21 % by volume (Percent). The outputs are a 4–20 mA loop (current sink) and RS-485 Modbus RTU. The analyzer runs on 9–36 VDC and draws 35 mA plus the current used by the analog outputs.

What hazardous areas and environments is it designed for?

OxyScout is engineered for Class 1 Division 2 (Zone 2) hazardous areas and has an IP67 enclosure for dust and water protection. Process and ambient temperature is 0 to 50 °C. The analyzer is rated up to 250 psi without the flowmeter installed. Higher ratings are available if a regulator is installed upstream. Extreme-heat and extreme-cold enclosures are available options.

Is Standard Sensors only for the Permian Basin?

No. Standard Sensors is based in Montgomery, Texas, and builds OxyScout for natural gas and oil and gas operators across U.S. basins.

How do I get a quote or talk to an engineer?

Book a 30-minute meeting to review your application and get a quote, or call (936) 259-4643 or email [email protected].

Reliability is Standard

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Book a 30-minute meeting to review your application and we'll send you a quote after the call.

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Or call (936) 259-4643 · [email protected]