gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
151104-1026 EST
The residual 60 Hz magnetic field around my basement, other placres in my home, and the yard is less than 10 microvolts. Where 20 mV = 1 gauss, and thus my residual is less than 0.5 milligauss. Outdoors below my 3 phase primary lines the result is still the meter residual noise level. In the past using a 5' by 20' one turn rectangular loop below the primary lines I could see variations in the output voltage. This had no filtering to remove high frequency noise.
With my probe adjacent to my 1.25" copper water supply line 5 milligauss. Adjacent to one 120 V feeder 100 milligauss, and the other feeder about 30 milligauss.
I used a 1 mfd capacitor in parallel with the magnetic pickup to reduce high frequency noise. The inductance of the magnetic pickup is 116 mH with a Q of 1.2 at 1 kHz, To resonate4 at 60 Hz would require a capacitor of about 65 mfd. With 1 ufd the resonate frequency is about 450 Hz.
.
.
The residual 60 Hz magnetic field around my basement, other placres in my home, and the yard is less than 10 microvolts. Where 20 mV = 1 gauss, and thus my residual is less than 0.5 milligauss. Outdoors below my 3 phase primary lines the result is still the meter residual noise level. In the past using a 5' by 20' one turn rectangular loop below the primary lines I could see variations in the output voltage. This had no filtering to remove high frequency noise.
With my probe adjacent to my 1.25" copper water supply line 5 milligauss. Adjacent to one 120 V feeder 100 milligauss, and the other feeder about 30 milligauss.
I used a 1 mfd capacitor in parallel with the magnetic pickup to reduce high frequency noise. The inductance of the magnetic pickup is 116 mH with a Q of 1.2 at 1 kHz, To resonate4 at 60 Hz would require a capacitor of about 65 mfd. With 1 ufd the resonate frequency is about 450 Hz.
.
.