noise

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Steve Smith
Pico Staff Member
Pico Staff Member
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Re: noise

Post by Steve Smith »

Thanks for the post and feedback regarding noise and noise control

The following article will help with features such as Bandwidth Limit/Hardware Filter (if using the 4X25 scopes) here, along with a number of techniques to help you maintain signal resolution when the noise forces an over-range condition as you mentioned.

The following forum post also looks at the sources of noise and is aptly titled “Why all the noise”

I hope this helps, take care…….Steve

josegumby
OneWave
OneWave
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Joined: Sun Aug 27, 2017 3:46 am

Re: noise

Post by josegumby »

Thanks Steve. The initial reason for my post was that I didn't quite understand why the ignition spikes seen on the battery voltage seemed to be AMPLIFIED, simply by connecting the current probe on the second channel.

I was just curious, as it seems like that shouldn't happen.

Thanks,
Curt

victor2k
TwoWaves
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Joined: Thu Jan 28, 2016 7:17 am

Re: noise

Post by victor2k »

Hello,
Someone know how to remove the noise from a TA018 clampmeter.In the attached file is the noise,laptop work on battery,no current is measured.BNC cable was checked and found good,the clampmeter can't be used to check injectors on petrol engines because of this noise at 630Hz.
Also I checked on the same laptop,same scope,same place the noise from K2 clamp for reference.
Best regards
Attachments
20210930-0004.psdata
(788.99 KiB) Downloaded 15 times
20210930-0003.psdata
(648.37 KiB) Downloaded 14 times

Steve Smith
Pico Staff Member
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Joined: Sun Aug 25, 2013 7:22 am

Re: noise

Post by Steve Smith »

Hello Victor and thank you for the post

I can see from capture -003 how the pulsations at 630 Hz would play havoc with low current measurements such as parasitic drain as the deviation post 5 kHz (lowpass) filtering is approx. 24 mA

For measuring gasoline port injectors on a +- 2 A input range these pulsations (whist present) should not impact on your measurement

Given the K2 clamp was measured in the same environment under the same conditions, you have highlighted the superior shielding of the K2 device (over the TA018) which is exceptional given the input range in capture -004 is +- 5 mA (with 5 kHz lowpass filtering)

I say this because the clear pulsations present with the TA018 (-003) are not present when using the K2 (-004)

Unfortunately Victor, there is no one-size fits all cure for what we can see with the TA108. The use of Bandwidth limit (whilst valid) is not going to eradicate these pulsations.

The environment in which the clamp is operating may well be the better solution here and I would ask if we can try an experiment away from the typical measurement location?

If we still have these pulsations present (at 630 Hz) in a new location this may well be in the clamp itself!

The TA018 is most certainly a good all-round performer given the initial costs by comparison to the Chauvin Arnoux K2 where the price reflects its unique performance during exceptionally low current measurements in the micro amp region

What we have between the K2 and the TA108 is both ends of the low current measurement spectrum when it comes to “choice of clamp”.

Both these clamps have an application and your example above has highlighted the limitation of the TA018

I hope this helps, take care…..Steve

victor2k
TwoWaves
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Re: noise

Post by victor2k »

Steve Smith wrote:
Tue Oct 05, 2021 11:24 am
For measuring gasoline port injectors on a +- 2 A input range these pulsations (whist present) should not impact on your measurement
Hello Steve and thank you for the answer
In the attached image you will find the reason of my question,on a 2014 Prius with port injection I can't see the opening moment of injector because of this noise
injector opening or noise..PNG
Is a major difference between the TA018 sold on different market ?My clamp was buyed from the north american market, was made in Taiwan.
Best regards

Steve Smith
Pico Staff Member
Pico Staff Member
Posts: 1150
Joined: Sun Aug 25, 2013 7:22 am

Re: noise

Post by Steve Smith »

Hi Victor, thanks for feeding back and including the image too.

I agree, whist we can determine the pintle lift event (approx. 484.5 ms) it is not conclusive and disappointing too?

How does this same event look with another clamp?

Could you confirm no filtering was applied?

Regarding "Is a major difference between the TA018 sold on different market ?"

A great question to which I do not know the answer. (Sorry)

I think the best way forward is a direct comparison using a donor TA018 with the 2014 Prius.

Where are you located Victor?

Take care.....Steve

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