There are many types of oxygen sensors used in process gas analyzers.  Some of the common types of oxygen sensors are electrochemical oxygen sensors and zirconia oxygen sensors.  Both of these oxygen sensors are used by Illinois Instruments.

The electrochemical oxygen sensors operate much like a battery.  Oxygen gas flows by an electrode and becomes a negatively charged hydroxyl (OH-) ion.  These ions move through electrolytes in the oxygen sensors to positively charged electrodes typically made of lead.  The (OH-) ion reacts with the lead and releases electrons.  The electron flow is measured and can mathematically be converted to an oxygen concentration.  Our Series 900 Oxygen Analyzers use this type of oxygen sensors.  Advantages of this type of oxygen sensors include ability to measure oxygen in hydrocarbon or solvent streams, accurate, and inexpensive.

Zirconia oxygen sensors use a stabilized zirconia ceramic to measure oxygen.  Platinum electrodes are painted on the outside and inside of the oxygen sensors.  The zirconia oxygen sensors are heated above 600oC.  At this temperature, the crystal lattice structure (how the molecules line up) expands allowing oxygen ions to migrate through the oxygen sensors.  Oxygen breaks down into oxygen ions at the electrodes of the oxygen sensors and travels through the oxygen sensors between the electrodes.  The flow of oxygen ions is either outward or inward of the oxygen sensors depending on the oxygen concentration in the sample gas compared to the oxygen concentration in a reference gas.  Our Series 800 Oxygen Analyzer uses this type of oxygen sensors.  Advantages of this type of oxygen sensors are wide measuring range and fast response.  The semiconductor processing industry has found that oxygen sensors with an extremely fast response time is important.  Illinois Instruments has sold a large number of oxygen analyzers into the semiconductor industry because of this.

Illinois Instruments' Series 900 Process Oxygen Analyzers offer unmatched versatility in high performance on-line oxygen analyzers.

Utilizing a variety of specially engineered electrochemical fuel cells, the Series 900 Oxygen Analyzers are designed to monitor oxygen within most industrial gases and atmospheres. These highly advanced instruments incorporate user-friendly software and the highest quality sensors to provide accurate, reliable results.

No matter what your measuring range, the Series 900 has an analyzer to suit your needs.

Trace Sensor (parts per million)
The trace sensor is designed for measuring 0-10,000 ppm oxygen in most industrial gas streams. This sensor, when used in a normal operating range, typically lasts 3-5 years.

Ultra-Low Trace Sensor (0-1 ppm)
This high performance sensor was developed for applications where continuous oxygen measurements are maintained between 0 and 1 ppm.

RACE™ Sensor
The RACE™ Sensor (USA and British patents pending) is a breakthrough in electrochemical technology. Our unique design prevents the sensor from being saturated by high levels of oxygen. With TURBOPURGE™, levels as low as 20 ppm can be reached from ambient air within 2 minutes. This sensor is unaffected by hydrocarbons or volatile atmospheres making it the ideal choice in applications such as wavesolder and reflow ovens.

The RACE™ Sensor is maintenance free and only requires infrequent calibration. No caustic electrolyte to monitor or replace. The RACE™ Sensor carries a 3 year warranty.

Percent Sensor
The Illinois Instruments percent sensor is capable of accurate measurements from 0 - 100% oxygen. Unlike most electrochemical sensors, this sensor is not affected by carbon dioxide.