Oxygen Monitor – OXY-SEN™

Oxygen Monitor

Oxygen Monitor

The OXY-SEN™ Oxygen Monitor is an economically priced percent oxygen monitoring system equipped with a standard measuring range of 0-100%. Available as an option, are dual 4-20 mADC recorder outputs that are scaled over 0-100% and 0-25%.

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Extended Life Oxygen Sensor

Expected Life upwards of 3-4 years

Acid Gas Resistant Sensor

Operates well in harsh atmospheres

Low Cost of Acquisition

Starting at $1250

Excellent Speed of Response

Responds instantaneously to changes in O₂


  • Measurement Range: 0-100% oxygen (gas phase)
  • Measurement Error: ±1% of full scale (at 77°F and 29.92” Hg)
  • Linearity: ±1% of full scale
  • Response Time: 90% of full scale in under 30 seconds
  • Sensor Type: Long-life ambient temperature electrochemical
  • Temperature Compensation: Standard
  • Operating Temperature Range: 40° to 104°F (5° to 40°C)
  • Warranty: 2 years on electronics and 1 year on sensor


  • Display: 3-1/2 digit liquid crystal
  • Input Power: 115/230 VAC, 50-60Hz or 24 VDC
  • Analog Output (Optional): 4-20 mADC scaled over 0-100% O2 and 0-25% O2(selectable by connector position).


  • Storage Temperature Range: 40° to 104°F (5° to 40°C)
  • Sample Gas Pressure Limits: < 2 psig (0.14 kg/cm2)


  • Dimensions of Electronics Enclosure: 5-3/4 in.(146.05 mm) Width 5-1/2 in.(139.70 mm) Height 1-1/4 in.(31.75 mm) Depth Note: All dimensions are without optional equipment
  • Dimensions of Sensor: 1.85 in.(47 mm) Height 0.9 in.(22.86 mm) Depth
  • Thread depth: 0.29 in.(7.34 mm) (exclusive of O-ring)
  • Thread size: M16 X 1
  • Weight (with 10’ of sensor cable): < 2 pounds (<0.907 kg)


Our CE approved O2 monitor features an extended life, ambient temperature electrochemical sensor that is extremely resistant to a variety of acid gases, including carbon dioxide. The front panel has an easy to read, 3-1/2 digit liquid crystal display. Input power to the OXY-SEN is 115/230 VAC, 50-60 Hz or 24 VDC . The OXY-SEN can be wall/panel mounted or used as a bench-top device.

O2 Monitor Designed for Percent Oxygen Measurement Applications

Our O2 monitor was designed primarily for applications where the user prefers to mount the gas diffusion end of the sensor through a chamber, glove box, reactor, etc. The diffusion end of the sensor has a threaded stock, providing an easy and convenient way of installing the sensor through the wall of a chamber, glove box, etc. by simply drilling and tapping an appropriately sized hole. Ten feet of coiled interconnecting sensor cable is supplied with each OXY-SEN Oxygen Monitor. For gas tight integrity, the extended-life sensor is equipped with an “O” ring that helps to form a gas-tight seal. One advantage of using a threaded sensor is that it eliminates the need to use sample pumps or air driven aspirators to provide sample to the sensor. An optional, flow through sensor housing is available for applications where external sampling is required.

Why Choose Us

For 25 years, our O2 monitor and other products have become known for their reliability, precision, and cost-effective pricing. Our instruments feature next gen sensor technology, and are manufactured as well as quality control tested in the United States. In fact, our product quality is emphasized throughout the manufacturing process starting with raw material vendor surveys through final assembly, testing, and system calibration. We’ve also earned an exceptional reputation for presale and after-market support. We’re committed to pairing you with the right O2 monitor for the right conditions and best possible outcomes.

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Related Application Notes:

Measuring CO₂ and O₂ in Bioreactors

Measuring CO₂ and O₂ in Bioreactors Accurate measuring of oxygen (O₂) and carbon dioxide (CO₂) is critical for a number of processes across a number of industries. From healthcare and veterinary medicine to landfills and even restaurants, the measurement and analyzation of CO₂ and/or O₂ ensures medical machines, food packaging, and more are safe, healthy, and up to standards. Today, we’re going to focus on the importance of measuring these two gases in bioreactors and how to obtain an accurate reading of both. What is a bioreactor? Before understanding how to measure CO₂ and O₂ in a bioreactor, it’s first important to understand what a bioreactor is and what it’s used for. A bioreactor, or sometimes referred to as a fermentor, is a vessel that supports a biologically active environment to grow a number of organisms including yeast, bacteria, fungi, and more. The process can either be aerobic, meaning results are produced utilizing oxygen, or anaerobic, meaning there is no presence of oxygen. The apparatus is able to do this by controlling pH levels, temperature, and airflow. The size and shape can vary slightly depending on its use, but they are typically made of stainless steel and are cylindrical. [...]

Glove Box Oxygen Analyzer

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Measuring PPM Oxygen for Welding Applications

Measuring PPM Oxygen for Welding Applications Not all welding applications require inert shielding gas. However when it does, use of an accurate and reliable trace oxygen analyzer is an essential tool.  TIG (Tungsten Inert Gas) welding of titanium requires the use of inert shielding gas, typically either high purity argon or a mix of argon/helium containing under 100 parts per million (PPM) of oxygen. Air contains 209,000 PPM of oxygen, so in order to create an acceptable atmosphere within the weld box (avoiding leakage of air into the box), a constant purge of inert shielding gas is normally applied. To help ensure oxygen levels within the weld box are at acceptable levels, a trace oxygen analyzer becomes a critical tool. Excessive levels of oxygen often lead to poor quality welds. The following video helps to describe the necessity of measuring trace oxygen in inert shielding gas. Caution should be exercised when selecting an oxygen analyzer for welding applications.  When PPM oxygen measurements are required, avoid analyzers that only measure percent oxygen levels. Most of these types of analyzers use electrochemical sensors designed specifically for percent oxygen measurements, not parts per million. In such cases, welders often interpret [...]

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