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Surprised at Low Household EMI Readings

I picked up a Trifield EMI100 meter to check for EMI noise around the house. After watching a few YT vids I was expecting some pretty high readings. Surprisingly almost everything was low. The unfiltered outlets where my system is plugged in measure less than 10 milllivolts with all equipment powered on. The worst was the bathroom GFCI outlet at around 65mV. I use a 10-year-old Blue Circle power conditioner, and that output is a few mV less than the wall outlet. The house was built around 1970, and outside of a new fuse box installed a few years ago, everything else is original.

Very happy with these readings as I was considering a power conditioner upgrade. The $150 Trifield meter seems to have saved me a few thousand bucks.

jaybe

Showing 2 responses by sns

sns
4,120 posts
 

Just went around house with my Trifield meter taking readings from various outlets, amongst the outlets measured were whole house, dedicated lines to my audio system, lines coming out of my power conditioner (transformer based), whole house lines with Audio Prism Quiet Line filters. Whole house with or without the filters and dedicated lines measured pretty much the same, lines out of my transformer based PC measured higher.

 

So, based on these measurements we can deduce my dedicated lines, the filters worthless, and those coming out of PC are less than worthless. Or we can deduce these readings not telling us much of anything. On the other hand, subjectively, these dedicated lines and power conditioning  have greatly reduced noise floor of my audio system, a great number of audiophiles report same with their dedicated lines and PC's. One can choose to believe the Trifield meter as the objective arbiter of noise on AC lines or they can choose their senses.

 

So some 

sns
4,120 posts
 

I too don't see any correlation to the need or not for power conditioner. I have Triifield meter, most useful in audio systems to measure for RF and EMF. I my case in which I have modem and router close to audio system, extremely high levels of RF led to me disabling wifi for what now serves as my audio only router, adding a second wifi enable router located  some distance from audio system serves as whole house router, RFI leakage or contamination of other equipment is a concern. EMF leakage from  transformers is another concern, these should be shielded so as to not contaminate sensitive circuits in equipment.

 

AC circuits are noisy for a whole host of reasons, much due to the many switch mode power supplies on modern electronic devices, thus, the reason for dedicated circuits for audio. Dedicated circuits alone generally not enough, most find noise floors further diminished via power conditioners. I don't believe any Trifield meter is going to serve as qualified arbiter as to whether you will benefit from power conditioner or not.

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