devoted to making a better vibration plate

EMF Measurement of VT Vibration Plate

Electromagnetic fields (EMF) are a combination of energy fields of electric field and magnetic field that are produced by electrical devices. Like other household electric appliances, Vibration plate produces EMF. The type of EMF produced by vibration plate is in the range of extremely low frequency EMF, or ELF-EMF. So far there is no clear evidence indicating EMF exposure would pose health hazard. The link between ELF-EMF exposure and various diseases is weak.

We performed in-house measurement of the EMFs generated by VT003F vibration plate. At the highest intensity setting, the maximum magnetic field strength measured at 6 inches above the footplate is 5.7 milligauss, and at one foot above it is 1.3 milligauss. Above two feet, the magnetic field strength quickly fades to ambient level.

Below is the measurement results of both magnetic field and electric field of VT003F vibration plate.

Model VT007 uses the same motor and the same control circuits. The EMF strength and pattern should be the same as VT003F.

VT003F Vibration Plate EMF Measurement

measure EMF
EMF Meter:
TriField EMF Meter Model TF2
Frequency Range: 40Hz - 100Hz
Accuracy: ±4% @ 50/60Hz
Max AC Magnetic Field Range: 100.0 mG
Max AC Electric Field Range: 1000V/m
Samples:
The testing samples are 6 units of VT003F vibration plates randomly selected from one production batch
Source:
The source is selected at the center of the footplate (right above the motor), where the maximum magnetic field strength is detected.
Distance from Source:
The meter is held vertically above the source in the distances of 6 inches, 1 foot, 2 feet and 4 feet, which is defined as the Distance from Source. These are the distances adopted in EPA's report on EMF measurement.
VT003F Magnetic Field Strength Measurement
Amplitude Setting: High
Median Value | Unit: milligauss (mG)
Distance from Source 6 In 1 Ft 2 Ft 4 Ft
@ 40 Hz 5.7 mG 1.3 mG 0.2 mG Ambient*
@ 30 Hz 4.5 mG 1.1 mG Ambient Ambient
@ 20 Hz 3.6 mG 0.9 mG Ambient Ambient
@ 15 Hz 3.5 mG 0.8 mG Ambient Ambient
*This test is performed in a room that is away from other EMF source. The testing room's ambient magnetic field strength is measured fluctuating between 0.1mG and 0.2mG.
VT003F Magnetic Field Strength Measurement
Amplitude Setting: Low
Median Value | Unit: milligauss (mG)
Distance form Source 6 In 1 Ft 2 Ft 4 Ft
@ 40 Hz 2.9 mG 1.7 mG Ambient Ambient
@ 30 Hz 1.9 mG 0.6 mG Ambient Ambient
@ 20 Hz 1.5 mG 0.5 mG Ambient Ambient
@ 15 Hz 1.1 mG 0.3 mG Ambient Ambient

The measurement results of magnetic field strength from the 6 samples show about 20% deviation from the medium values.

VT003F Electric Field Strength Measurement
Electric field value does not change as frequency or amplitude change
Median Value | Unit: V/m
Distance form Source 6 Inches 1 Foot 2 Feet 4 Feet
Electric Field Value 65 V/m 44 V/m 25 V/m 20 V/m

EMF Comparisons

For the comparison, we use the same TriField EMF meter that measured VT003F to measure a few randomly selected household electric appliances. The results are as below.

Magnetic Field Strength Measurement of Random Household Electric Appliances
Unit: milligauss (mG)
Distance form Source 6 In 1 Ft 2 Ft 4 Ft
Hair Dryer 11 mG 2 mG Ambient Ambient
Microwave Oven Beyond meter range** Beyond meter range Waving
42-100+ mG
Waving
7-35 mG
Electric Oven 22 mG 8 mG 3 mG Ambient
Electric Range 14 mG 3.8 mG Ambient Ambient
Refrigerator Ambient Ambient Ambient Ambient
Pressure Cooker 14 mG 3.3 mG 0.5 mG Ambient
Vacuum Cleaner 56 mG 18 mG 2.7 mG 0.4 mG
**TriField EMF meter's maximum measurement range is 100 mG.

Data from EPA Publication

For the reference, the EMF measurement in the table below are from 1992 EPA publication: EMF in your Environment - Magnetic Field Strength of Everyday Household Electric Appliances.

EPA Data of Household Electric Appliances
Unit: milligauss (mG)
Median value of the category
Distance form Source 6 In 1 Ft 2 Ft 4 Ft
Hair Dryers 300 mG ? 1 mG - -
Microwave Ovens 200 mG 40 mG 10 mG -
Electric Ranges 30 mG 8 mG 2 mG -
Refrigerators 2 mG 2 mG 1 mG -
Washing Machines 20 mG 7 mG 1 mG -

EMF Shield

EMF's electric fields part can be easily shielded, but the magetic fields are much more difficult to shield. Magnetic fields can be reduced by enclosing the source in a type of alloy like mu-metal, a nickel-iron soft ferromagnetic alloy.

There are some kind of small coil devices or chips offered in the market, claiming these devices can shield EMF. That is not ture.

Comment or Question

© 2017 - 2021 Vibration Therapeutic® All rights reserved.