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I am looking for a cheap oxygen sensor for application in a gas analysis system. The cheapest I can find is a Zirconium based car exhaust sensors, which require extremely high operating temperatures to produce significant output voltages, approximately 600 degrees centigrades. I am looking to enclose it in a plastic container, but the very large operating temperature is worrying me. Have any of you dealt with such a sensor? If so, do you think it's heat isolated enough for my application, to be enclosed within a plastic container? This is an example of a sensor I was thinking of.

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  • \$\begingroup\$ There are other likely better methods, like a galvanic o2 sensor, or one of the uv style sensors.(see co2meter) \$\endgroup\$ – Erik Friesen Jun 27 '13 at 11:28
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I have never tried using one in a plastic container, but the body is made of metal so heat transfers relatively well. After a flame test or testing plugged into an actual exhaust I made sure to not touch the sensor with my bare fingers.

A generic plastic container will almost certainly not be able to deal with the hot operating temperatures, especially if you have to rely at all on the exhaust to heat up the sensor.

Depending on the application, you could try getting exhaust tubing with an O2 sensor port and flow your gas through the tubing past your sensor. The tubing is relatively cheap to get, you may even be able to find something at a local junk yard.

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  • \$\begingroup\$ do you know of any other type of car exhaust sensors that do not operate at such high temperatures? \$\endgroup\$ – l3win Jun 27 '13 at 5:14
  • \$\begingroup\$ Not that I'm aware of; car exhaust by it's nature is very hot. What do you want to do with an automotive O2 sensor? There may be a better way to do it. \$\endgroup\$ – helloworld922 Jun 27 '13 at 6:45
  • \$\begingroup\$ they are relatively cheap, and I need an O2 sensor in the $100 range for gas analysis. \$\endgroup\$ – l3win Jun 27 '13 at 20:54
  • \$\begingroup\$ Some quick google-foo tells me that automotive O2 sensors have a built in heating element for getting O2 readings when the engine/exhaust is cold or idling. Don't know if this is enough to get continuous readings or if it will damage your enclosure, but it is something to play around with if you have a spare/junk sensor around \$\endgroup\$ – crasic Jul 27 '13 at 4:15
  • \$\begingroup\$ As long as the gas flow is large enough, the localised increase of temperature will not affect much the casing. Be sure to use a proper control unit to keep its operating conditions within specifications. \$\endgroup\$ – FarO Dec 25 '18 at 21:08
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Did you look into these: http://alphasense.com/industrial-sensors/pdf/O2A1.pdf ? The form factor is common to several manufacturers.

You will need some analog circuit to interface it to an ADC.

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