Friday, February 9, 2018 Episode 494 12:00 PM EST   Sal La Duca Environmental Assay, Inc. What you did not know about Electricity, EMF's & IEQ -Part 2

Field Detection and Measurement In the realm of EMF there are four categories of investigation. There is some overlap, in that some categories can act as carriers for the others, and there is a varying level of detail, which can vary extremely depending on the needs of the client, and the desired level of resolution.

IAQ & EMF Parallels EMF measurement, is similar to IAQ Particulate “measurement” in certain respects. Whereas IAQ Particulates can be “measured” as to Size and Geometry, they can be “quantified” as to Abundance, and Distribution. Similarly EMFs can be “measured” as to Electric or Magnetic Fields, and they can also be “quantified” as to how many of them occur in a certain unit of time, being the Frequency. A lot has to do with the wavelength. When dealing with RF (an inseparable combination of Electric and Magnetic fields), possibly similar patterns emerge due to the type of Modulation. 

Field Detection and Measurement Shown above are the general types of measurement that can be carried out, although they are not all- inclusive, and the most basic being Amplitude. That may be all that is required, as today 2018-02-07 I visited with a client that had a wiring problem related to their HVAC AHU, which caused a strong Magnetic field in the bedrooms 20 to 30 feet distant. Guiding the HVAC techs on what to test and what to test for, the wiring problem was resolved, and the Magnetic field eliminated.

Field Detection and Measurement The Waveform and Harmonics measurements provide clues as to what piece of equipment is involved.

Field Detection and Measurement Problems can emerge from the type of wiring employed, any wiring errors present, nearby power lines, metallic-to-electric systems interconnections. Determining the cause, and the intensity (a.k.a. Relevance) is what makes the assessment valuable, because then you can know what you can do about the concern, if anything.

Field Detection and Measurement The first check during a generic EMF visit is to check for Electric fields. Non-contact Voltage Probe

Field Detection and Measurement Some investigators use an E field meter, costing around $2000, which I cannot justify, because the E field level will vary inch by inch, and will Not tell you what the cause is, or the polarities involved, which are very relevant.

Field Detection and Measurement I use the BV (Body Voltage) surrogate as shown below when time and resources are available (as this is a bit time consuming), which is equipment-inexpensive (total materials outlay may be $100) and will identify the sources, and their polarities.

Field Detection and Measurement The AC voltmeter used can be any DMM (Digital Multimeter), having a standardized input impedance of 10,000,000 Ohms. Lower impedances, such as 50,000 Ohms, typical of bargain basement automotive meters, will not be sensitive enough to detect the Electric fields desired.

Field Detection and Measurement The second measurement generally made is of Magnetic fields. For this I use a 3 Axis Gaussmeter (Model 4080).

Field Detection and Measurement Gauss Master or Dr Gauss It is single axis, readily available, and at $40, your investment would not be a loss. To get proper measurement with this unit, you would slowly rotate it to get the highest reading, and it is then aligned with the field.

Field Detection and Measurement To verify measurements from either gaussmeter, I use a clamp-on current probe and meter to identify the source.

Field Detection and Measurement It can be used as the voltmeter for BV measurement, Ohmmeter to check materials conductivity (for shielding), and current to identify the source of a Magnetic field.

Field Detection and Measurement Detect Harmonics The third check is to detect the Harmonics, which starts to get into Spectral Analysis of field- generating signals, is to use an AM radio, such as the one shown.

Field Detection and Measurement To get better definition of the Harmonics, you’d have to use a Power Quality analyzer, which is a combination Oscilloscope and Spectrum Analyzer in one unit, such as the one shown at right.

Field Detection and Measurement To check the RF (Radio Frequency) background, my last check usually, things get complicated. Quick. Do you want the absolute maximum value over a range? Do you want the average value over a range? What range are you interested in? Or do you want the values relative to MPE1 recommendations? Do you want a meter with numbers, or a probe with LEDs? Do you want to see a spectrum?

Field Detection and Measurement Shown at right is the spectrum from 1 MHz to 2.7 GHz involving the most commonly used frequencies, inclusive of 2.4 GHz WiFi, which is not present here, as I measured this in a field, away from “civilization.”

Field Detection and Measurement I generally do not have the luxury of taking spectral measurements, so I typically simply measure the Peak and / or Average over a range with an RF meter such as the one shown below.

Summary Assuming that EMFs travel at the speed of light, the wavelength of 60 Hz is about (186,000 miles / second) x (1 / (60 cycles / second)) = 186,000 x 16.6 (ms/cycle) = about 3000 miles. When the wavelength is large, relative to human dimensions (as when dealing with power systems), we are generally within the Near Field, and Electric and Magnetic components are measured separately. Thus the need for a Gaussmeter (Magnetic Field meter) and an Electric Field meter. While Electric Fields (caused by Voltage) are pervasive, and the same strength 24-7, Magnetic Fields (caused by Current) can vary second by second. In the latter case, a Gaussmeter is used to guesstimate the suspected source, and a clamp-on current measurement is used to verify the identity of the source. A video is provided to expound on Clamp-on Current measurement.

Summary(cont) When the wavelength is small, relative to human dimensions, we are generally within the Far Field, the Electric and Magnetic components are inseparable, and we measure the entity as “Radio Frequency (RF).” Should the RF source be very close to us, as in a cell phone by the ear, then we are experiencing Near Field effects, instead of Far Field effects. There is world of difference. 

Summary(cont) While Far Field effects (as in walking is an airport with many cellular users), generally deal with reduced tissue penetration, Near Field effects (as in you using your cell phone) produce thorough tissue penetration, which is why Near Field exposure produces tumors and Far Field exposure doesn’t.

Summary(cont) Harmonics are somewhere between Near Field and Far Field, and can occur in both, depending on the source. They are difficult to measure, and more difficult to deal with, partly due to lack of enough talented individuals that know how to measure them. Metering is also affected, in that meters that do no account for Harmonics when measuring Electric or Magnetic fields, can provide values that may be off by as much as a factor of 50, bringing us to Wonderland, with Alice!