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Measuring line noise and power conditioners

I recently purchased a Trifield EMI (Dirty Electricity) Line Meter to measure noise coming from my outlets. To my surprise, my $500 power conditioner (name withheld to protect the potentially innocent) appears to not filter any noise per the Trifield readings. In fact, with some of my outlets the measures are higher through the conditioner’s outlets, than the measures coming straight out of the wall. The manufacturer denies anything is wrong with their conditioner, claiming the Trifield is measuring the wrong frequencies. Can anyone explain?

output555
twoleftears's avatar
twoleftears
5,315 posts
 

With that Trifield you can also detect ghosts.

In their YouTube demo videos, I'm not sure what meter Isotek uses, it might be the one from Alpha labs or similar.  Search: noise sniffer.

slaw's avatar
slaw
21,021 posts
 
@erik_squires ,

What’s wrong with that?.

Frankly, I heard a substantial improvement in SQ, then I realized I had the meter. It seemed to confirm, In a measurable way, the increase in SQ I was experiencing.
three_easy_payments's avatar
three_easy_payments
2,097 posts
 
@erik_squires 

You are measuring starting at 20 kHz and going up. That is, these devices START measuring noise at the upper limit of human hearing.

It's hard to imagine noise on your line only affecting one portion of the frequency range.  So in other words if you reduced noise that's being measured above 20khz why wouldn't you expect that same filtering to affect the entire range even in areas that aren't being measured by the meter?  Do they make current filters that reduce noise between 100hz and 1Khz??? (for example)  That makes zero sense to me.


slaw's avatar
slaw
21,021 posts
 
+1 @three_easy_payments,

You said it better than I could.
erik_squires
16,009 posts
 
It’s hard to imagine noise on your line only affecting one portion of the frequency range. So in other words if you reduced noise that’s being measured above 20khz why wouldn’t you expect that same filtering to affect the entire range even in areas that aren’t being measured by the meter?

This problem is kind of a Venn diagram.  A conditioner which starts at 10 kHz will hopefully also clean up 100 kHz.  A  conditioner which starts working at 100 kHz won't necessarily clean up 10 kHz.

Of course, coupling can occur later, and there will be a frequency high enough that it stops working at too.

So, you have a meter which measures RFI, which shows reduced noise, and the power conditioner happened to reduce noise in the audible spectrum too.  That's luck.
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