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CO2Meter Announces New Zirconia Oxygen Sensors

A first hand glance at the new Oxy-Flex Oxygen Analyzer and Zirconia Oxygen Sensor System, now available for a variety of applications in combustion control, industrial boilers, gas, coal, incubation and many others.

Nitrogen oxides (NOx) are an unwelcome byproduct of combustion. The Gas Analysis Probe Oxygen Analyzer can be used to control oxygen levels in flue gas.

IntoN2 manufactures a line of high pressure, high purity nitrogen generators in their factory located in Minden, Nevada. These nitrogen generators are primarily used for laser cutting and specialized manufacturing, but are used in other industries requiring up to 5 nines (0.99999%) of high-purity nitrogen.

Because they generate nitrogen, I was curious when IntoN2 began purchasing our TR250Z 25% oxygen sensors, and decided to give them a call. I spoke with Charlie Winans, a control engineer at IntoN2, and asked why they needed an oxygen sensor in a nitrogen generator?

Charlie explained that one of the features IntoN2 has incorporated into their generators is an oxygen sensor to detect if trace amounts of oxygen are present in the final N2 gas. This additional feedback loop is a “double check” that further verifies the purity of the gas generated.

I asked Charlie how he found us.

“I googled oxygen sensors,” he said. “I was looking for a sensor that ran on 24 VDC, and output an industry-standard 4-20mA signal to make it easy to integrate into our system.”

Additional requirements were that the oxygen sensor would be maintenance free, and did not corrode or expire like traditional chemical cell sensors.

“And you had the oxygen sensor in stock for immediate shipment,” Charlie added.

After completing his research, Charlie and his team chose our TR250Z 25% oxygen sensor with tube sampling. They have been integrated into IntoN2’s full line of generators, and are performing as required.

I asked Charlie how they got into the nitrogen generator business.

“Our company couldn’t find the right nitrogen generator for our laser cutters, so we built one,” he said. When they discovered there was a market for high-purity nitrogen generators, they began to manufacture them under the IntoN2 brand name.

According to Charlie, stand-alone nitrogen generators reduce costs between 75-90% compared to delivered gas services.

“Our nitrogen generators are high pressure. They can boost up to 4,300 psi, a unique feature in the industry,” he added.

Nitrogen is considered an assist gas in the laser cutting industry. Using an assist gas allows material like steel or aluminum to be cut faster with a cleaner edge. In addition, high-pressure gas also blows material out of the cut (called the kerf) to maintain a cleaner cut edge.

If you work with gases like we do at CO2Meter, you already know that the ideal gas law PV=nRT shows that absolute gas concentration decreases as temperature increases. This relationship is important to anyone measuring oxygen levels during combustion, fermentation, distillation or algae production.

But like they say, “a picture is worth a thousand words.”

That’s what we discovered when we measured the change in oxygen gas levels in a sealed environment using our UVFlux 25% Oxygen sensor and Gaslab software. Using the built-in RS232 protocol, the UVFlux sensor samples both the oxygen level and the temperature inside the sensor once per second.

Over several minutes we raised the temperature of the sample from 24C to 34C, and were able to see in real-time the oxygen concentration in the sample drop from 20.6% to 19.8%.

click image on right for larger view.

Note the internal sensors components are corrected for operating temperature over the range. No compensation is made for the temperature of the gas being measured. Also note the change in oxygen level measured slightly lagged behind the change in temperature.

In addition to temperature, the % relative humidity will have an impact on the oxygen concentration in a sample. At the same pressure and temperature, a volume of oxygen at 100% humidity will contain less oxygen molecules than if there were no water.