ASSAP: Paranormal Research
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Probably the most popular instrument used in paranormal research, after cameras, is the EMF meter. Here are some frequently asked questions about the use of this equipment.

Q: How are EMF meters used in ghost research?
A: There are several schools of thought but they all appear to agree that fluctuating or 'unusual' electromagnetic fields are a sign of paranormal activity. Some people say that ghosts emit such fields while others maintain they disturb the fields already present (such as the geomagnetic field). Yet others say that fluctuating fields are a side effect of paranormal activity. To some people EMF meters are ghost detectors with an obvious use for ghost research.

The problem with all these ideas is that there does not appear to be any formal, or even an informal, study demonstrating a connection between EMF meter readings and paranormal experiences. A few people claim to have had unusual readings while having a paranormal experience but this could have been a coincidence and we do not know for sure that their experience was truly paranormal. See 'What kind of study would demonstrate that EMF meters detect paranormal activity?'

A few people use EMF meters to detect experience-inducing fields (EIFs) which are low magnitude, highly variable magnetic fields that cause some people to have hallucinations. Unfortunately, EMF meters are not capable of detecting such fields. They don't have the sensitivity or frequency response to do so - see here.

Q: How do we know paranormal activity is associated with electromagnetic fields?
A: We don't! No one seems to know where the idea came from - see 'How are EMF meters used in ghost research'.

Q: What do EMF meters actually do?
A: See here.

Q: What do EMF meters measure?
A: See here.

Q: How do you use an EMF meter in ghost research?
A: The theory is to look for unusual variations in the fields measured by the meters. This is usually done by comparing readings with a baseline. Such baselines are usually done by walking around a room with the meter and noting the range of measurements found. Then the meter is left still and watched (ideally coupled to a data logger) to see if there are any readings outside the baseline range.

The problem with this method is that electromagnetic fields vary both according to position and over time. So the field at a particular position in a room may depend on the distance of nearby electrical appliances. And it can vary over time depending on whether those appliances are operating and what they are doing. What is more, concealed electrical wiring behind the walls (and under floor boards) of a room can produce different fields over time according to what power load it is carrying. That power load may be from electrical devices in other rooms.

A further problem is that in large buildings, particularly commercial ones, there may be a three phase supply. This can cause alterations in the electromagnetic field in a room because the phases interfere with each other - see here.

So, to obtain a reasonable baseline you would need to leave a meter the same particular place for at least 24 hours to monitor the natural variation in the building over that period. Even then, a reading outside that baseline range will not necessarily be caused by anything paranormal. It could simply be that electrical loads are higher on the night of the ghost vigil, possibly because of the presence of ghost researchers!

A much better way of using baselines is to use a positional method. In that way you compare how the readings from two identical meters, one in a haunting hot spot, the other in a nearby location where no paranormal has been recorded. See here.

Q: What can cause false positives with EMF meters?
A: There are many natural causes of fluctuations or peaks in electromagnetic field readings (see here). The meters were designed to pick up mains frequency fields (50-60Hz) so many of the peak readings will be caused by the operation of electrical equipment. However, the meters are also highly sensitive to moving metal, such as steel or iron, that distorts the local magnetic field. So someone walking past the meter with something metallic in their pocket could cause a spike.

Q: What kind of study would demonstrate that EMF meters detect paranormal activity?
A: In essence, you would need to show that unusual fluctuations or spikes in meter readings coincided with someone having a paranormal experience. However, there are severe problems with this, even in theory, never mind practice. Firstly, how do we know that someone is having a truly paranormal experience and not simply a xenonormal one? Given that most sightings of ghosts prove to be misperception or near sleep experiences when investigated, it is likely that many apparently paranormal experiences are not paranormal at all.

The second major problem is that you cannot compare one EMF meter 'spike' with another. The readings are only accurate at mains frequency. Readings at other frequencies may be completely wrong. A single reading of '10' might indeed be 10 at 50 Hz but really 20 at 300 Hz. It could also be a combination of different frequency components that add up to '10'. What this means is that, unless you are measuring only mains frequency (which doesn't normally interest ghost researchers) the reading is likely to be wrong. It is therefore impossible to compare readings for different frequency readings. Worse, you've no ideas what any of these frequencies are anyway. So you've no idea if one reading might be the 'diagnostic signature' of a paranormal event and another just someone turning a light! See here for more details.

A third problem is that you need to get enough paranormal experiences accompanied by readings to rule out coincidence. We know that there are many natural causes of 'spikes' and fluctuations so we need a lot of times when they coincide with paranormal experiences to be statistically significant. Given how rare such experiences are, this could be very difficult.

In conclusion, it is almost impossible, even in theory, for an EMF meter to be a 'ghost detector'.

Q: What kind of EMF meters are best?
A: If you want to use an EMF meter for paranormal research there are some types to avoid. You should certainly avoid single axis models. Because electromagnetic fields have direction, as well as magnitude, you need a three axis meter to measure them. If you use a single axis model, the reading will vary, even if the field magnitude does not, because of the direction in which the field is presented to the meter.

Q: If EMF meters are not suitable for detecting possible paranormal activity, what alternative is there?
A: To be able to compare different magnetic field readings, you need a magnetometer rather than an EMF meter. Unfortunately, these are expensive. If you DO get such a magnetometer, you need one with flat frequency response down to 0 Hz, so that you can record EIFs. A triple axis fluxgate magnetometer would be suitable. See MADS, for instance. While such a set up could detect EIFs, there is no existing study to show that whether it could detect paranormal activity.

© Maurice Townsend 2011