|Ghost hunters are finding more and more that the presence of ghosts or other paranormal entities can cause detectable energy disturbances in the
local electromagnetic spectrum. Consequently, many ghost hunters are arming themselves with a vast array of tools and technology.
The apparent most-favored piece of techno-equipment for the modern ghost hunter is the EMF detector. This "simple" device, though of the greatest
assistance to the ghost hunter, is the winner of the "Most Confusing Online Purchase" award. While there is an increasing popularity for using more
scientific tools to detect ghosts and spirits, the retailers selling these tools haven't done much to help you to decide what you really need to be using.
If you look to buy any of the available detectors online, then you'll see what a mess is being made of retail "knowledge."
Please know that I intend to grossly oversimplify many of the very complex scientific understandings about the fundamental forces of the physical
universe. Hopefully my research and this article can help clarify a few things about EMF detectors and their cousins. Besides, these devices are just
too darn expensive to pick one that may not be useful for you.
What are EMF detectors?
An EMF detector is used to detect ElectroMagnetic Fields (EMF) or changes in E.M. fields. Depending on the manufacturer's choices for the device,
each EMF detector is set (calibrated) to detect only a specific set of E.M. wavelengths, and/or E.M. frequencies. EMF detectors vary widely in what
electromagnetic wave "type" that they detect. You may prefer to choose a detector that cannot "accidentally" detect cell-phones, house wiring and
What is Electromagnetism, and What are Electromagnetic fields?
To start with, magnetic fields are usually naturally produced by magnetic materials and other items. Electricity, in actual fact, has to do with the
amount of energy, or charge, a sub-atomic particle or structure has; it isn't merely the stuff that powers your computer and vacuum cleaner. To
simplify a complex science, a changing magnetic field produces an electric field. Similarly, a changing electric field generates a magnetic field. When
magnetism and electric charges interact, they create...electromagnetism.
A small science lesson about the spectrum (range) of electromagnetism.
I don't want to bore you, but it may help you to understand what the specs (specifications) mean when you want to buy an EMF device later. I
apologize in advance for any headache that might incur. But this information is what will be presented by the retailers and manufacturers on "what"
your EMF detector "detects." You can skip the science lesson entirely if you like, and just go direct to "EMF. The Names, terms, and what they mean."
Keep reading, because you might need this info, or the full spectrum and frequency chart, to make heads or tails of the information presented about
your prospective meter. Mostly, these scientific measurements on the frequencies can help you determine if your EMF meter is suitable for a
EMF. The Names, Terms, and what they mean:
Detector vs. Meter
-Detector: just that, it detects, and then flashes a light or audible alarm when it detects a field strength that is at a certain preset level.
-Meter: same as the detector, but features a fast reacting needle gauge or numbered digital display to show you what the strength of the detected
What they measure
They can (depending on the device) measure the electric field, magnetic field, and radio frequency. The common favorite for many paranormal
researchers are the Multi-Field Meters, which can measure two to three of these fields.
Names and Types of EMF Meters
The terminology for these devices is not always consistent from one manufacturer to another. For example, an EMF meter may be called an AC
gaussmeter, an electromagnetic field meter, a field strength meter, an electrosmog meter or an EMF detection meter.
A meter that monitors the combined magnetic and electric field strengths are usually known as Gaussmeters, Teslameters, or "Natural" gaussmeters.
RF Meters are for monitoring microwave and radio frequencies. Radio frequency meters measure in the general range of 1 Hz to 30 GHz.
AC or DC meter?
AC meters detect EM fields created by many things, including man-made electricity. DC meters simply detect smaller or weaker strengths, as direct
current (DC) doesn't create as strong a field as alternating current. AC and DC do not specifically refer to electrical power (like batteries and 110v
current), but EM fields similar in nature to electric power.
EMF Listening Devices
It is possible to actually listen to EMF energy levels and patterns, and sometimes this proves a very effective means of investigation of paranormal
events. Although it is less quantitative, it provides immediate and very personal feedback.
Single axis and Triple axis meters
Because electromagnetic fields are oriented in space, a sensor will only detect the field properly if it is aligned with the field. A single axis meter has
only one sensor in it. Therefore to get a correct reading with this type of meter, you must slowly rotate the meter until you find the maximum reading.
This will be the correct reading. If the meter is turned 90° from the maximum reading, it will read nearly zero. It is easy to understand how it is possible
to get a lower than actual reading if the meter is not properly aligned.
A three axis meter has 3 sensors in it, all aligned at right angles to each other. Therefore, this type of meter is always correctly aligned and no
rotation is required to get a correct reading. This type of meter takes less time to use but generally costs more that its single axis counterpart.
Field/Signal Strength, and Detector Sensitivity
At what distance from a source of a field can I use a meter?
That is, what is the range in distance for a meter to detect a field?
All meters have a range of exactly ZERO feet.
All meters and detectors, EMF meters, gaussmeters, electric field meters, RF/microwave meters, etc. can only measure the strength of the field AT
THE LOCATION OF THE METER. The meters can be placed in stationary positions or used like mobile probes while walking around during an
What distinguishes one meter from another is the sensitivity. In other words, what is the smallest field strength that the meter can detect? A meter with
sensitivity of 0.1 mG (0.1 milligauss) is ten times more sensitive than a meter which can only detect down to 1.0 mG. While the meter which is more
sensitive can be successfully used further away from the source of the field, it is still only measuring the field at the location of the meter.
In looking for a more sensitive meter, compare the minimum sensitivity rating of a particular detector to another. How effectively a device can detect a
field depends on the strength of the field at the source, the pattern of radiation from the source, and the rate that the field decreases with distance.
Without knowing a great deal about the nature of the source of any particular field, it is impossible to determine at what distance a given meter will
begin to detect a field. Depending on the type of field (magnetic, electrical) or type of wavelength (radio, microwave, UV, etc.) and the strength of the
source, your detection range (from the source) could be as little a few millimeters away, to over a dozen feet away.
To give you an idea of the sensitivity required of these devices to detect certain things, here are some examples of the magnetic field strength
(source strength measured AT the source):
The human brain magnetic field:
10^-9 to 10^-8 gauss, or 0.0000000001 to 0.000000001 gauss, or 0.0000001 to 0.000001 mG (milligauss), or 1 to .1 nG (nanogauss).
The Earth's magnetic field: 0.31 to 0.58 gauss, or 310 to 580 mG (milligauss).
A typical refrigerator magnet: 50 gauss, or 50,000 mG (milligauss). A refrigerator magnet can be detected (depending on your detectors sensitivity)
from approximately 2-3 inches away. Since the source strength (on direct contact) is a whopping 50,000 mG, but is only 1 or 2 milligauss a few
inches away, you can see that EM field strength drops sharply the farther away it is from the source.
Some meters can display magnetic strength as a tesla. One tesla is equal to 10^4 gauss, or 1,000 gauss, or 1,000,000 mG (milligauss).
For microwave/RF sensitivity on meters, they usually will detect output power in mW/cm2 (milliwatts per centimeter squared). This really isn't a lot of
power, as a key-chain laser pointer puts out power somewhere between 1 to 5 mW/cm2.
For Electric sensitivity on meters, they usually will detect output power in or kV/meter (kilovolts per meter).
Very little information is available on the field strength levels of environmental electric fields, but they might vary from 0.1 kV/m to 0.5 kV/m in a
residential setting to as high as 10 kV/m directly under power transmission lines. Electric fields within one foot of small appliances are in the range of
0.02 to 0.2 kV/m, while the field immediately adjacent to the heating wires of an electric blanket can approach 10 kV/m.
Now that your brains are falling out of your ears, let’s look at an example of a "typical" EMF device.
(Sorry, this isn't a real EMF meter that is for sale, but it is based on what you will find when you look to buy a meter.)
Uber-Geist EMF Detector (see #1)
Magnetic: 0.1 mGauss to 199.9 mGauss (see #2)
Electric: 1 V/m 0-500 V/m (see #3)
Single Axis (see #4)
Runs on one 9 volt battery (not included) (see #5)
Frequency Bandwidth: 30 to 300 Hz (ELF frequency range) (see #6)
Accuracy: ±4% at 50-60 Hz (see #7)
1. First off, there is a numbered gauge, so this isn't just a "detector", but a meter as well.
2. Magnetic- This guy is REALLY sensitive to magnetic fields, but you don't have to worry about magnets unless you get too close. (A standard
refrigerator magnet is about 50,000 mG).
3. Electric- 1 to 500V/m is OK, but it is quite sensitive to large electrical fields. So you will have to be VERY careful not to pick up power lines or many
other things when you are indoors. Does this model allow you to choose if you use the electric field detector, or is it always on?
4. Single Axis - Hmm, this means that if you will have to move the detector around to find what direction the source is coming from. Then you will have
to play the hot/cold game and move around to find where the source is coming from.
5. Runs on one 9 volt battery (not included)-They never come with batteries. You've got to remember about batteries.
6. Frequency Bandwidth: 30 to 300 Hz (ELF frequency range)-This meter/detector also detects radio sources, low ones, so that rounds out this
meter, which turns out to be a Tri-field meter, or multi-meter.
7. Accuracy: ±4% at 50-60 Hz-What's this? Let me explain: Mains power, or the AC electric power that runs through power lines, is usually set at 50
or 60 Hz cycles. Most of the U.S. is at 60 Hz, most of Europe is at 50Hz. So this unit, when detecting electric fields, has a plus or minus 4% accuracy.
i.e.: The meter detects 100 V/m, but the actual field strength (at the meter) is 96 – 104 V/m.
Seven things to get better results when purchasing and using an EMF device
Look for EMF detector/meter models where you can adjust the threshold level. This will let you "fine tune" when the device detects fields. This is
especially useful if your EMF detector is sensitive enough to pick up common household items.
You can try using an EMF meter outside (sensitive high RF and electrical especially), and a gauss meter inside. You might get more accurate
readings by limiting when you use an "over" sensitive device.
When one meter detects a huge spike in current or radiation, use another meter to balance things out to determine a true measurement.
One huge factor in determining your purchase - detectors are usually cheaper than meters.
Remember to bring enough batteries to keep the meters on the entire length of the investigation.
Try to document the measurements in each room of the house or building in your initial walk-through, and then do more investigation in the room or
location that emits the most unexplainable readings.
Don’t forget, household appliances are known to cause fluctuations with EMF readings. Some of the most common culprits for interfering with an EMF
reading are televisions, computers, computer monitors, electrical outlets and faulty wiring within the location. Virtually every electronic device has the
potential to interfere with the reading.
Especially for the beginners, expensive isn't better. Often, an ELF (Extremely Low Frequency) detector is best for paranormal research, as the -
pardon me- cheaper models tend to prevent embarrassing mistakes. The sensitivity levels of these inexpensive devices isn't great, so they won't go
off unless you are almost touching a power source, exposed wiring, or other field source. Ghosts often interact on MANY levels of the EM spectrum,
so you don't lose out by "only" detecting their presence in the low radio wavelengths.
Unfortunately, there isn't any proof that these EMF devices ARE detecting ghosts, but many spirits CAN cause a device to react to their presence, as
they do with E.V.P. So don't get bogged down on the fancy features of a technological ghost hunting tool; researchers have encountered ghosts for
years without needing a beeping, flashing, screaming, whistling box-thingy. The tools are supposed to help you keep your mind on what you are
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