Category Archives: EMF Meters

EMF Meter Facts & Safety Levels Testing

EMF Testing Indoor Air Quality Radon Gas Testing: 214.912.4691 Dallas – Houston – Austin – Fort Worth

Powerline Home Safe Distance Cell Phone RF Surveys

Cell Tower Site on High Voltage Power Line near homes in residential area in North Dallas – EMF Testing and Surveys

EMF Testing / Magnetic Field Survey & Safe Distance Measurement Services

EMF testing for those concerned about living near powerlines and feeders is available for commercial clients and limited residential with reports that range from verbal to complete reports with photo documentation and graphics. We also provide consultation on viable strategies and products for EMF protection. We travel all over Texas and cities in adjacent states including Dallas, Houston, Fort Worth, Austin, San Antonio and Oklahoma City.

RF (Radio Frequency) Scans and Evaluations – Maximum Permissible Exposure (MPE)

We test RF energy for frequency and amplitude in order to find sources and evaluate safety with respect to FCC regulatory, compliance and precautionary guidelines, and to determine potential interference issues between wireless routers, cell phone repeaters / boosters, Radio Frequency Identification (RFID) systems, and wireless microphone / audio / video data systems.

Magnetic / Electric / RF & EMF Shielding Consultations including proper grounding

If you have an issue with electromagnetic energy that is either a safety issue or causes equipment interference, we are fully qualified to assess, troubleshoot and make sound recommendations to fix or mitigate the situation.

Radon Gas Measurements & Surveys (Short / Long Term Testing)

With a background in radon and radiation safety, we are capable of evaluating and reporting on radon gas levels, how they compare with EPA standards and whether a mitigation solution is called for.

EMF Testing for Electrical Wiring Issues Indicated by Excessive EMF Fields

Whether you believe in the safety hazards of EMF or not, the most common source of high EMF fields inside the home is improper wiring which fails to conform to current NEC code. ScanTech can detect and direct repairs on electrical wiring that manifests as an abnormal magnetic field.

Preliminary Construction Surveys / Property Transfer Phase I Environmental Site Due Diligence Survey testing regarding Indoor Air Quality (IAQ) – EMF Consultation for Safety and potential EMI – Radon Testing for Multi-Family Dwellings and Commercial Buildings.

We are often called out to site before a structure or complex is erected in order to survey and communicate any possible issues and the potential impact of nearby power lines, substations, transformers, cell towers and other EMF/RF generating sources. We also make construction recommendations for minimizing electromagnetic field emissions for safety and electromagnetic Interference concerns with sensitive manufacturing and research equipment.

Indoor air quality testing for VOC levels regarding Certificate of Occupancy permits according to City of Dallas Green Ordinances. Also known as the 804.2 Post-Construction, Pre-Occupancy Baseline IAQ Testing which is a 4 hour test for 500 uG / m^3 or less of VOCs.

Magnetized & Radiation Contaminated Metals, Stone and Imported Products

ScanTech has been in the radiation survey business for over 10 years and is routinely called upon to investigate cases of suspected radioactive contamination and magnetized ferrous metals which can cause unusual issues. Our instrumentation includes several Geiger counters with capable of detecting Alpha and Beta particle emissions, X-Rays and includes specialized Gamma radiation scintillation detectors.

Weak Cell Phone Signal Reception Issues & Wireless LAN Problems / RFID Interference

Weak Cellular Phone (including 2G / 3G / 4G LTE) & Wireless Strength Measurements with consulting for correction / mitigation in commercial buildings, residential and multifamily properties with poor coverage, slow data rates and dropped calls for all major telecom and communications carriers including Sprint, T-Mobile, Verizon, AT&T for smartphones, tablets, iPads, etc. Radio Frequency Identification system troubleshooting and interference issues investigated. We also perform FCC RF Compliance surveys for MPE (Maximum Permissible Exposure) including rooftop antenna installations.

Implanted Biomedical Device EMF / EMI Measurement Compliance Surveys and Testing for Patient Safety

Medical Device Compliance Testing (Pacemakers, Implantable Defibrillators, ICD’s etc. – Medtronics, St. Jude Medical, Boston Scientific, Mortara) for individuals returning to work or home after implant surgery to identify potential hazards from AC/DC Magnetic and Electric Fields, Microwaves, RF and general EMI (Electromagnetic Interference).

Hospital Infant Anti-Abduction Security Systems

ScanTech troubleshoots RFID integrated systems designed to protect neonatal care facilities that employ systems such as Hugs by Stanley Healthcare and MyChild by McRoberts Security Technologies.

Electrostatic Discharge (ESD) Testing, Consulting And Evaluation for Commercial, Industrial and Biomedical Companies / Applications / Clients

We have the equipment to determine the sheet resistance of ESD flooring material and if anti-static grounding is working as well as the ability to identify troublesome materials and processes which can cause equipment malfunction and electric shock / fire / explosion hazards. We can also measure relative air ion counts, humidity and the direct DC static voltage on surfaces (positive or negative) up to 30,000 V to determine which objects in the environment may be damaging your static sensitive equipment.

Indoor Air Quality (IAQ) Surveys to Determine Relative Air Cleanliness PM2.5 / PM10 / HEPA Filtration Efficiency / Formaldehyde / VOC / CO2 (Carbon Dioxide) / O2 Oxygen % Concentration & Contamination for Commercial Building and Industrial / Occupational Atmosphere Evaluations with expertise in Nanotoxicology and Medical Environmental Illness Testing

We have time based datalogging air laser analysis available to characterize particulate matter such as small particle contaminants (down to 0.5 microns such as bacteria) and large particle counts (2.5 um and larger) for potential pollen, dust and mold detection which are also known as RSPs. (Respirable Suspended Particles) We can also check for formaldehyde concentrations and VOCs (Volatile Organic Compounds) levels from outgassing materials such as pressed wood flooring or glues and other binders.

Elevated CO2 (carbon dioxide) levels are indicative of Sick Building Syndrome and poor air exchange characteristics in a structure.

New nanomaterials on the market have raised concerns about the potential toxic effects of nanoparticles (such as carbon nanotubes, titanium dioxide, silver NPs, etc.) in particulate, aerosol, aqueous forms and their in-vivo effects.

Commercial, industrial, occupational health and limited residential applications.

http://www.indoorairqualitytestingdallas.com/

OSHA Sound / Noise Level Surveys for Safety Audits

Sound (Commercial) & Industrial Safety field surveys and measurement including for acoustic OSHA sound and STC (Sound Transmission Class) noise levels / ordinances / testing (meeting ANSI & IEC Type 2 standards) to determine compliance and evaluate potential issues with excessive or disruptive noise.

Photometric Glare & Illumination (Lighting Level) Surveys for Safety, OSHA and City Ordinance Compliance

Photometric mapping to identify poor / insufficient / excessive illumination, security camera glare, ATM lighting security assessments, ADA lighting requirements / compliance, and privacy. Many cities have enacted ordinances which limit the amount of light emanating at the property line at night in foot candles. (fc) We can also measure lighting flicker rates which can cause headaches and other performance issues as well as evaluate possible disruption of circadian rhythms which lead to insomnia and lack of restful REM sleep.

Metallurgical Analysis & Consulting

Materials analysis for ferrous / non-ferrous metals / alloys. Tools and tool steel quality evaluations for carbon content. Also magnetic / RF / electric shielding capability, corrosion resistance, heat resistance, degree of temper, quench methods, elasticity, weathering, and electrical quality consulting. Metamaterial composite research for nanotechnology, biomedical, and exotic applications. (graphene, nanoparticles, carbon nanotubes, nanodiamond, etc.) Radioactivity testing for scrap metal or other suspected products.

Using the Wrong EMF Meter for EMF Testing and Home Inspections: A Case Study in Professional Judgment

EMF Inaccuracy Analog vs. Digital

EMF Meter Comparison for Home Inspection with SIGNIFICANT DISAGREEMENT in magnetic field readings

I always find it both interesting and gratifying when clients who hire me already have their own meter and yet are willing to pay an additional fee to interpret the results. They will call and express concern about either a home they are considering purchasing or one they are already occupying as they are alarmed at the high readings they see on the EMF meter they purchased.

What instigated this post is two separate clients a week apart who both purchased a Trifield 100XE analog EMF meter and got readings that indicated a field of 100 milliGauss or greater. I was a bit skeptical of this being true and for good reasons:

1) It was based on my long experience in doing EMF testing and surveys in the Dallas/Fort Worth area.

2) And what I know about using something other than a high quality meter for making a decision on something as important as where you and your family including children plan to live for the next 5 – 20 years.

Now, I am not putting down either the meter, the manufacturer or the homeowner for using this type of meter for a professional inspection. But as you will see in the story I tell, it is more than worth the money to have an expert opinion as a “sanity check” because of the likelihood that you can either get a false positive or a false negative as it were.

As you can see in the above picture, the 100XE is set to the 0 – 100 mG scale and is nearly pegged at 100 mG. The digital reference meter I use shows nowhere near that level at 7.49 milliGauss. That error is off by more than an order of magnitude which means that the Trifield is reading more than 10 X the amount that is actually present. And yes, my meter is calibrated as I periodically check it against another meter.

In this case, if the homeowner had merely relied on the meter they purchased online, it would have potentially meant that they would have passed up a home they might have been otherwise happy with based on erroneous information. This is more time and hassle for them, the seller, agents, etc. all based on a faulty needle indication.

EMF Meters Home Inspector

Two Analog Trifield Meters compared with a digital reference meter

The second case came a week later with another Trifield 100XE on the scene. In this case, it was not nearly as inaccurate, but it still reads 2.5 mG while the reference meter reads just under 1 milliGauss. Not as dramatic, but still enough difference that a family with young children might have shied away from this property when it was not really an issue.

Now as an aside, take a look at the reading of the Natural EM Meter (blue label) to the right. This is one of my personal meters and it reads low at less than 0.5 mG. More accurate, but it is still reading lower levels than what is actually present. So why do I even use this meter? Because one thing I do like about analog meters is that they are good for seeing trends and odd fluctuations – but I never use them for absolute values on a survey.

You may think I am saying the Trifields are not any good, etc. but they do have their uses as long as you understand their accuracy limitations. To be blunt, the reason these have become so popular is because of the interest in the paranormal and ghost hunting fields and the ways in which they can be customized with outputs, alarms, backlighting, etc. but these features are not of direct use to a serious prospective homeowner or professional EMF inspector. There is more commentary on this in the following post regarding a technical conversation I had with the manufacturer.

At the end of the day, a proper EMF inspection is about more than just reading a meter; it is about having judgment and recognizing errors when they do not fit with conventional experience and wisdom. It is about being knowledgeable about the different kinds of meters, single axis vs. triple axis, true-rms averaging and how the frequency range of an individual model of meter can weight the readings differently. It is also about risk assessment, diplomacy and seeing a larger picture than just a scary needle sweeping across a meter face.

SCANTECH EMF CONSULTING  214.912.4691

Why A Professional Digital EMF Meter Should Be Used For a Survey

In my previous post, I commented on a recent phenomena this past year in which a number of customers who had purchased an EMF meter online or elsewhere to do a survey on a prospective property contacted me after finding what appeared to be anomalously high readings and wanted a second opinion.

Every time it was a Trifield 100XE which is easily recognizable with the yellow label, brick-like construction and familiar needle movement which distinguishes it as an analog meter versus the digital EMF versions. The variations in accuracy varied from moderate to extreme when compared with my 3-axis professional grade meter and I began to wonder what was going on.

I recently contacted the manufacturer of the Trifields (AlphaLab Inc.) and one of their electrical engineers cleared up the mystery as to why the readings seemed to vary so wildly. The 100XEs are typically sold as frequency weighted which means that even slightly higher frequency magnetic fields will add even more to the indicated reading than a meter with a “flatter” frequency response. Also, they measure from 40 Hz – 100 KHz which is a VERY broad band for an AC gaussmeter used in a EMF survey for testing the influence of power lines. Typically, for measuring 60 Hz and any relevant power harmonics, an EMF meter that measures in the range of 30 Hz – 3 KHz is a broad enough range and even 30 Hz – 300 Hz will cover 60 Hz plus the 5th harmonic. The strength of the harmonics gets progressively weaker as frequency increases.

60 Hz Power Line Harmonics

60 Hz Power Line Harmonics

In other words, you may have a 3 milliGauss magnetic field at 60 Hz, but a weaker magnetic field at 120 Hz will weight the reading even more strongly and register as 6 milliGauss when in fact it is only 3 mG.  (from an excerpt on the company website) So the standard Trifield 100XE weights the “harmonics” (multiples of 60 Hz such as 120 Hz, 180 Hz, etc.) differently than a flat frequency EMF meter. Ordinarily, any instrument that is frequency weighted has an attendant chart which tells you how much more weight at different frequencies is measured than over the non-weighted frequency point of the meter.

Below is an example of this sort of chart for the Natural EM Meter (blue label) which is very different from the 100XE model. (This was taken from the vendor website – I know the word “frequency” is misspelled)

EMF Meter Frequency Magnetic Field

Natural EM Meter (not 100XE) Frequency Weighting Chart

A little confusing?

Based on my experience, I can interpret the chart, but what I wanted was the chart for the 100XE model Trifield and I could not find it on the manufacturer’s website. This is what initiated the call to the vendor. When I spoke with an electrical engineer, she explained that the 100XE is not particularly accurate (rated as +/- 20% according to the specs on their website) and is not recommended as a reference for any type of serious EMF survey.

Furthermore she went on to explain that even the manufacturer has NO SUCH chart for the 100XE model so you really don’t know what you are reading and how much is due to the 60 Hz magnetic field that you are interested in and how much is distorted or misrepresented by the high frequency harmonics.

And to further dispel another myth, the Trifield is named for the fact that it measures 3 types (tri) of fields: magnetic, electric and radio frequency, NOT because it is a 3-axis meter in every mode as the RF (radio frequency) measurement is only in SINGLE or 1-axis and will alter greatly depending on the orientation of the meter with respect to the RF source.

But I am not disparaging the company at all (they make some excellent equipment for certain applications and their website is very informative) and the 100XE has some viable uses, but it seems to be more towards something more subjective like the paranormal field rather than what a serious EMF consultant would choose for an official EMF testing survey. I DO like the needle movement as it does help you to track slow or fast fluctuations so I do keep a Trifield with me, but the difference is that I know under what circumstances it can be used and also when I would not use it as an absolute for helping a client decide on a property decision because of the proximity of power lines.

EMF Meter Phone Apps – Do They Work and/or Indicate Dangerous Conditions?

EMF Meter App for Android Phones and Tablets

EMF Meter App for Android Phones and Tablets (and similar ones for iPhones / iPads) with design based on the Trifield 100XE analog meter

I was recently contacted by a commercial client who was concerned about purchasing office space in McKinney due to a number of factors:

1) The close proximity of some imposing high voltage powerlines directly outside of his office

2) Recent inexplicable computer equipment failures in the office

3) That cute app that you can download onto Android (and probably your iPhone) that measures magnetic fields.

So does this app really work?

DC Magnetic Field Reading (not 60 Hz AC Powerline frequency)

DC Magnetic Field Reading (does NOT read 60 Hz AC Power Line frequencies)

Yes, but NOT in the manner that you think. It works as far as measuring the NATURAL DC magnetic field of the Earth which varies according to locale and the proximity of ferromagnetic building material. But DC means there is no frequency or fluctuation in the field; it is by definition 0 Hertz or 0 cycles per second as opposed to the North American power grid frequency of 60 Hertz.

What is the difference?

Quite a bit.

There is very little evidence that DC magnetic fields are harmful in any way (except higher intensity fields than Earth normal to those with certain biomedical implants such as pacemakers, ICDs, implantable defibrillators, etc.) and in fact there are patents on medical devices which use low level DC fields to speed the healing of broken bones.

But look at the overall reading above showing 834 milliGauss (mG) with the bar graph registering ominously in the red. And speaking of which, the “green – yellow – red” color coding scheme is something I object to in EMF / RF testing instrumentation as it is completely arbitrary from a technical standpoint and induces needless fear-mongering with regard to actual safety levels. It is done partly as a marketing feature to make it look cool, but also as an attempt to give some kind of intuitive user knowledge about the EMFs in the environment, but in fact instills false confidence and infers incorrect information.

While I can give a brief overview of bio-electromagnetics to my clients while consulting, diving into the details is an incredibly complex subject that even a B.S. in Electrical Engineering does not fully prepare you for. You also have to have biomedical knowledge of human and cell physiology (thus, my continuing education and credentials as a biomedical engineer) plus at least some understanding of disease epidemiology and probability / statistics which makes this a truly interdisciplinary field that few understand well.

While the Earth’s magnetic field is typically around 500 – 600 mG, this can be either concentrated or attenuated significantly when inside of the frame of a steel building. What can potentially scare people with this app is that they read about Swiss safety limits of 10 mG, 2.5 mG or even 1 mG and then they assume this reading means they are in some sort of danger. I can guarantee that this meter does not measure anything having to do with health or safety with respect to AC power lines.

The reason for having DC magnetometers built into a smart phone is so that it can relate relative positions of the phone (such as when you turn it on it’s side) with respect to the Earth’s magnetic field and respond accordingly.

It is a cool app to play with and I have it on my phone, but it is not something I would use for a professional EMF inspection, nor would I use it to advise a client on the health, safety or risk conditions of their environment.

Radiation & EMF Mythology Promulgated by Media and TV Shows

Sometimes I am dismayed by the lack of what I consider to be “common sense” science knowledge and critical thinking skills displayed by not only the mainstream public, but also by supposedly educated individuals. Even some experienced medical doctors I have personally met display an alarmingly poor understanding of even basic physics and draw conclusions that range from dubious to plain ridiculous.

While I have enormous admiration for anyone who achieves a doctorate degree, particularly in the health sciences field. and I am not detracting from their actual medical skills and experience which I know well outweighs my ability in that arena, the intersection of how physical forces and energies interact with the human body exceeds a knowledge of anatomy, experience with disease and how to perform surgery.

As a recent example, I was watching an episode of Dr. House which is a medical mystery drama series loosely based on the character of Sherlock Holmes, but set in our modern 21st Century. I am a huge fan as I enjoy the acerbic wit, sharp dialog, medical jargon, dark human dynamics and brilliant acting which is fairly consistent throughout the show’s history.

In Season 2 Episode 19, Dr. House orders Chase to investigate the patients house for sources of radiation with a Geiger counter. Chase dutifully walks around with the device while holding the probe up to different appliances while the ominous crackling rate of the counter increases to a near continuous ripple of static. At one point in a cell phone conversation, Chase laments to Dr. House: “You know how many electrical devices give off radiation?”

I am well aware that the series takes a very liberal Hollywood treatment of distorting facts to fit a story better, but given that there was a legitimate episode which involved accidental radiation poisoning, I found this on the edge of inexcusable. The kind of radiation that a Geiger counter detects has nothing to do with the electromagnetic fields found in any kind of modern home appliance, even a microwave.

Geiger counters typically detect Alpha radiation if the detector itself has a mica window, (high energy Helium nuclei) Beta Radiation, (high energy electrons) Gamma Radiation, (high energy photons) and in some cases X-Rays depending on the model.

The energy levels of EMF and RF even well up into the microwave and thermal infrared range simply do not have enough energy to ionize atoms and thus set off such a detector. And by the way, thermal radiation causes molecules to vibrate more rapidly, which is a very different effect than knocking subatomic particles (such as electrons) off of an atom.

But this anecdote underscores a fundamental issue that I find in educating the general public:

Most people do not understand the electromagnetic spectrum, the difference in physics and physical effects that different regimes of frequency manifest and will often confuse one with another. Visible light is a form of electromagnetic radiation, but it is not the same thing as X-Rays or gamma radiation. This lack of understanding can lead to a fear of things which have no demonstrable effect on the human body, and I have clients purchase instruments or shielding gear that is not designed for the concern they have.

More than once I have seen a customer purchase an RF meter (instead of an EMF meter) to measure power lines and vice-versa. Or the meters are of insufficient consistency, quality or display their information in a confusing or misleading manner such as labeling different readings by color code (green, yellow and red) which have no real world correlation to any particular standard.

This is why consultant services such as ScanTech exists – not simply to read numbers on a meter, but to supply context and meaning to what exactly is being measured and what risk factors / effects are associated with that.

EMF Consulting and Safety: On the Importance of Instrument Calibration

When quoting a job or project to a customer, a question that comes up from time to time is:

“Are your meters calibrated?”

An understandable query, but the answer may surprise you.

EMF consulting is a specialty field that most of my clientele have very little familiarity with and it is wise to try and ascertain if you are getting good data for the money paid.

However, my extensive technical experience covering over 25 years in several interdisciplinary fields (including experience and certification in the calibration of instrumentation) has given me a rather unique perspective and stance about the relevance of this question.

My short answer is that as long as it is a digital meter of semi-professional grade or better from a reputable company and is in proper working order from the date of purchase, observing calibration intervals (which are usually a holdover from the old analog days) is not as important as some may think PROVIDED that the meter is known to be initially accurate within a certain % depending on the application. Very often, you can perform a cross-check with other meters and as long as they are in close agreement, that indicates proper operation.

The only exception to this is if:

  • The particular meter/model is known to have serious accuracy / unpredictable performance issues such as one model I discuss on this site.
  • Damage from impact, fluid intrusion or a corroded battery has or is suspected to have caused operational issues to the sensors / internal electronics.

This may sound unprofessional or even contradictory to other post on the importance of using a high quality meter, but I have pondered this issue for a long time and I can give a number of strong reasons for this position:

1) Unless you are doing actual research grade work, (such as in academia or R&D) are calibrating other instruments, or you are performing mission critical work (such as an infusion pump dispensing medication to a patient in a hospital) you simply don’t need the absolute best accuracy to accomplish the mission of the instrument.

Close is good enough for almost any application of EMF surveying.

For instance, if an EMF meter reads 1 milliGauss, (mG) but the true NIST traceable reading is 0.9 or 1.1, being off by 0.1 mG or 10 % should not be the deciding factor between buying a home or not.

2) Readings of magnetic fields, radon and RF naturally fluctuate over time, so what is more important is looking at an average.

3) Different meters have different frequency weightings so no two meters will be in complete agreement anyway.

4) You cannot always trust a calibration sticker. A dirty secret in the industry is that a lot of money is spent on calibrations that are incorrectly performed or not even done at all. I know this as a fact because I have not only had calibration technicians tell me, but I was IN the instrument / radio calibration business myself.

Just because an official looking piece of paper says that a meter is accurate, you are still trusting the honesty of the person / company that certifies the equipment and often there is not a clear “chain of custody” that holds anyone responsible or that the right / qualified individual actually performed said calibration. I am not saying calibration isn’t worth doing, nor am I accusing any calibration company in particular, just that you should maintain a healthy amount of wariness about this issue.

A controversial subject analogous to this is the autograph authenticity industry – try Googling that and I believe you will find some of the stories very eye-opening and sobering as to the real value of an expert’s opinion when volume vs. quality directly impacts the bottom line. And frankly, it is easy to forge a very official looking calibration certification paper for most instruments.

5) Different types of measurements can be very difficult to get accurate because of the physics involved. Not everything is as simple as knowing the speed of a vehicle, for instance. (something which can be measured with excellent accuracy)

For example, received and transmitted RF power is notoriously difficult to nail down due to reflections, constructive / destructive interference, etc. so that getting within 3 dB (or 50 % accuracy) is considered reasonably good and the reading can change depending on your antenna gain, frequency weighting or just moving the instrument a few centimeters to one side.

In plasma physics, if your measurements are within a factor of 2 of calculated values, that is considered valid. In other words if you expected to get 5 and get 8 instead, (a 50% + error) that is still in the acceptable ballpark of even high level research data.

6) Calibration at annual intervals is an old and in my professional opinion for most instruments, unnecessary “feel good” tradition that no longer matches the actual requirements of modern solid state electronics that have a fair degree of drift compensation and stability compared to older, analog devices.

If you have a new instrument made from a reputable manufacturer and after only a year it is found to be significantly off, then I would strongly suspect it was defective / improperly calibrated to begin with.

And this is not just my opinion; a number of modern instruments now manufactured have recommended calibration intervals that are either upwards of 10 years + or are even guaranteed for the life of the instrument barring serious damage such as that from a fall / water immersion, etc. which would probably place the meter in a category of “inoperable and uneconomical to repair” so it would be replaced with a new one anyway.