how to analyse my lambda sensor waveform ?

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eric989
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how to analyse my lambda sensor waveform ?

Post by eric989 » Wed Jun 02, 2010 5:54 am

Dear all,
These days, I tested two cars' lambda sensor,all are Zirconia Lambda sensor.

The waveform is very strange, at least for me.I know little about lambda sensor. :lol: There are a lot of vertical lines upon the traces.And the traces are very big/wide.

Could you tell me that what the traces meaning ? Is there any fault in the sensors or I make a wrong Picoscope software setting ?

I enclosed the waveform files for you. Many thanks .
Attachments
chevrolet lambda.psd
chevrolet lambda
(499.79 KiB) Downloaded 572 times
toyota lambda.psd
toyota lambda
(255.85 KiB) Downloaded 446 times
Eric Chen
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Re: how to analyse my lambda sensor waveform ?

Post by NigeC » Wed Jun 02, 2010 7:26 am

Hi Eric,

Change your collection time to 1s/div or 2s/div as a start then increase to fast idle and back to idle to see it reacting to changes in oxygen. :wink:
It is working :)

Regards,
Nige
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Re: how to analyse my lambda sensor waveform ?

Post by Autonerdz » Wed Jun 02, 2010 1:54 pm

Eric,

The O2s in your captures are working fine. The reason you have a fat trace with all the vertical lines is noise from ignition events etc. Filter the signal to shave all that hair off for a cleaner signal.

Just curious...why are you using PicoScope 5? Looks like you did this with a 3000 series scope? PicoScope 5 cannot make full use of the capabilities of that scope. PicoScope 6 will.

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Re: how to analyse my lambda sensor waveform ?

Post by eric989 » Thu Jun 03, 2010 5:40 am

NigeC wrote:Hi Eric,

Change your collection time to 1s/div or 2s/div as a start then increase to fast idle and back to idle to see it reacting to changes in oxygen. :wink:
It is working :)

Regards,
Nige
Change the time base, Ok. Thanks, Nige.

Regards,
Eric
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Re: how to analyse my lambda sensor waveform ?

Post by eric989 » Thu Jun 03, 2010 6:23 am

Autonerdz wrote:Eric,

The O2s in your captures are working fine. The reason you have a fat trace with all the vertical lines is noise from ignition events etc. Filter the signal to shave all that hair off for a cleaner signal.

Just curious...why are you using PicoScope 5? Looks like you did this with a 3000 series scope? PicoScope 5 cannot make full use of the capabilities of that scope. PicoScope 6 will.

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skype: autonerdz
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In North America
Hi Tom,

About "Filter the signal to shave all that hair off for a cleaner signal." Yon mean activate Lowpass Filtering ?

I am always using PicoSope 6, not PicoScope 5. The chevrolet lambda.psd file I captured with 3423. The toyota lambda.psd file I captured with 4223.

It is interesting that I can filter the signal of toyota lambda.psd file, but can't filter the signal of chevrolet lambda.psd. I thought the filter function is within the software, have no relationship with the hardware.

Many thanks,
Eric
Attachments
filter toyota lambda.psd
It is "toyota lambda.psd" I posted before, but I activate the Lowpass Filtering now.
(254.37 KiB) Downloaded 379 times
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Re: how to analyse my lambda sensor waveform ?

Post by Autonerdz » Thu Jun 03, 2010 2:12 pm

Much better, Eric :D

The reason I thought you were using Pico 5 is because psd is a Pico 5 extension. Pico 6 saves psdata file extensions. I see now they appear to be psdata files renamed to psd. I'm easily confused :?

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Re: how to analyse my lambda sensor waveform ?

Post by Dave Hill » Thu Jun 03, 2010 9:46 pm

Why would the files need to be "re named"?

This all looks a little "dodgy" I think?

Pico 6 saves with a *.psdata file extension, whereas Pico 5 saved with the *.psd format. Whats going on?

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Re: how to analyse my lambda sensor waveform ?

Post by eric989 » Fri Jun 04, 2010 1:09 am

Dave Hill wrote:Why would the files need to be "re named"?

This all looks a little "dodgy" I think?

Pico 6 saves with a *.psdata file extension, whereas Pico 5 saved with the *.psd format. Whats going on?
Hi Dave,

Why I rename psdata to psd, it is because that "The extension psdata is not allowed" in this forum.

regards ,
Eric
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Re: how to analyse my lambda sensor waveform ?

Post by Peter704070 » Fri Jun 04, 2010 7:40 am

Hello

I use a Mac on a daily basis and cannot open PSD files, could someone place the scope patterns on the forum in a different format.

Sorry to be a pain but very interested in seeing the scope patterns.

Thanks Pete

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Re: how to analyse my lambda sensor waveform ?

Post by Dave Hill » Sat Jun 05, 2010 5:32 pm

Hi Peter

I have the same problem when I browse on an iphone or ipad. I don't know if there is an "app for that" yet?

Often people post their waveforms in a common image format. A *.gif is ideal.

Eric

Sorry for my scepticism. I didn't know that the psdata file type was not accepted for upload. Weird that isn't it!

As Nigel has suggested, its a good idea to have a lot more time on screen than you have selected. The Automotive pre sets are a little dated now. The newer software & hardware allow you capture massive amounts of data & the superb zoom facilities mean that you can analyse any part of your capture with ease.

As for the noisy signal, I wouldn't be too concerned about it. Yes it can be filtered out, but in reality you can see the trend & you still have the ability to see the detail needed to draw your conclusions. Don't forget to "challenge" the sensor when scoping. Snap throttle tests can reveal a lot! :wink:

Cheers all

Dave

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