oxygen sensor

Hi all...I currently have an ab ML 1100 with a program that needs to incorporate a PID loop based on an O2 sensor. I have no experience with O2 sensors and I am looking for either a good off the shelf sensor to work with my controller or simply figure out how to pull in the data from the current Lamda sensor i already have. This is an automotive sensor on an exhaust system on a generator. If anybody knows anything about O2 sensors and how to pull the raw data off any help would be greatly appreciated. I basically need to know how to pull in the data to my controller utilizing my analogue inputs. all searches that i have tried so far are pretty much criptic. Thanks in advance for your help!

What kind of oxygen measurement?
Dissolved oxygen in water? ppm? ppb?
Excess oxygen in fossil fuel products of combustion?
Oxygen in the atmosphere of a carburizing furnace?
Oxygen in the surrounding environmental atmosphere, level of breathable oxygen?

this will be excess O2 after combustion from a generator. I would imagine this would be PPM...how ever i am not sure.

Portable or permanent in-situ oxygen probes, combustion analyzers, are used by boiler and furnace services to monitor products of combustion, in which oxygen is typical in low fractional percentages, like 2.4%.

They generally use a Zirconium oxide sensors which needs to be hot (1200°F?) before it will operate and generate an oxygen signal.

Outputs are digital indication, voltage or current 4-20mA, sometimes digital, like Modbus.

Power is AC or DC or battery, depending on style.

If I remember correctly from my "Gear Head" days the O2 sensor on a Gas Engine produce a voltage when there is a lack of oxygen. Usually 5 VDC or less (just confirmed this with my Mechanic Friend). Danw is correct in that they do have to be hot before they send the signal.

So I guess you could bring in that signal with a 0-10v analog module. Given that you only have 1/2 the range available, some accuracy will be lost but it "should" work.

Edit: The output is scaled in % of O2. 0vdc would be about 21% and 5vdc would be 0% best I can tell.

I've used gas phase O2 sensors from Alpha Omega with good success. Not cheap, but very reliable. They have 4-20 mA output proportional to % O2 among other things.

http://www.aoi-corp.com/products/carbon_dioxide_analyzers/series_9500/default.html

When you say generator are you talking about a power generator or an atmosphere (endothermic or exothermic) gas generator?

Lambda probes need heat, so you either need to use a heated probe or have the tip in a location where it will be hot enough. As for the signal, the most you are going to get is somewhere in the 1200 mV DC range.

I believe that in automotive applications the sensors run around 450 mV.

This is on a natural gas power generator....to be more specific a v-10 ford 100kw genset. optimally i would like to use the current o2 sensor on it and incorporate that dat directly to my PID loop.....I just don't know how to read the signal from a lamda auto o2 sensor

Just Googling 'Ford V-10 Natural Gas Generator' suggests that it's a Motorcraft DY1093 or DY1180 heated O2 sensor.

Isn't the sensor already connected to the engine's ECU ? Or do you have a second sensor just for your process control ?

What's the goal of knowing the O2 level in the exhaust ? Are your trying to build an external fuel mixture control ?

My guess is that a universal signal conditioner that can accept a +/- 1.0 volt signal and convert it to a 0-10V signal that the MicroLogix analog inputs can accept is a good way to go. If you just run the voltage signal directly to the MicroLogix the resolution will likely be too low.

This is usually done by a stand alone air/fuel ratio controller, see link for one brand.

http://www.altronicinc.com/catalog-downloads.shtml#engine-products

http://www.altronicinc.com/pdf/engine-controls/epc-50(e)-8-12.pdf

DANW keep pushing the in-situ. They have a private company that helps them with communications to other devices (SCADA, PLC, HMI, etc.) This company I hear is great. They have an engineering base of 1000+ thanks to Phil and this great site. I also hear that guy is handsome (so my wife says).

we are testing a completel different gas to run the natural gas generator engine. biomass gas. wood gasifier. the throttle body on the engine already is controlling the amount of fuel to the pistons. we are trying to control the mixture ourselves for experimental/data logging purposes. The natural gas engine is generally controlled by a pressure venturi system. we have removed that as our system does not function in this fashion. we function off of vacuum. we have already successfully done this on a ford 351 van and run it across the US three times on wood. essentially the same engine minus two pistons. however we manually controlled the mixture via a choke lever. we need to eliminate this and have our automation system handle this completely. in order to do this i simply need to measure the excess o2 for our sweet spot. then input the data for our PID loop for our mixture throttle.

Now it sounds really cool !

See if you can eyeball the part number, then we'll know for sure the voltage range and we can decide whether to wire it directly to the 0-10V DC inputs on the MicroLogix, or to use a signal conditioner.

It really is just a small voltage signal, under 1 V DC.

here is the numbers directly from the sensor...

FORD 2FA
F88F-9F472-EA
0 258005 809/810
2060480 12V 982


I haven't had any luck finding a pin out diagram or schematic of this. it has four wires. 1 black, 2 white, 1 grey. I assume the black is -12v and the whites are +12v and the grey is the signal. however all of this is speculation. any help on this is greatly appreciated!!!! We are in crunch time minus zero for investors....

http://home.earthlink.net/~jcgebhart/o2sens.html

This is probably a Bosch part.

So the two white wires are definitely the heater; hook up 12V to these and it will heat the sensor to operating temperature.

Gray should be connected to motor ground/DC Common.

Black is the voltage signal. This is what you'll measure with a voltmeter, or connect to the Analog Input terminal on the MicroLogix.