Instrumentation

by Maurice Townsend

This article originally appeared in Anomaly 27

Recently there has been an explosion in the use of instrumentation on paranormal investigations. It is now quite usual for an investigation to involve the use of such things as infra-red cameras, digital thermometers and electric or magnetic field meters. But are there any problems with this new widespread use of electronic equipment?

Already the use of instruments is giving rise to new ideas, new theories and even claims for new paranormal phenomena. In the normal course of events this could only be welcomed. But what if some of these ideas actually result from lack of understanding of what the instruments are measuring? We would be in danger of going down more blind alleys, which is the last thing our subject needs right now. That is what this article is designed to forestall.

Many of the physical quantities now being routinely measured on investigations are little understood by non-scientists. As an illustration of how complicated these things can be, I will concentrate on one particularly popular area in investigation: electromagnetic field measurement. This example can be generalised to other areas as a general approach to the whole subject. Hopefully it will lead investigators, particularly less experienced ones, to profit from the use of instrumentation while avoiding the pitfalls.

Why use instruments?

For over a century paranormal phenomena have been studied more or less scientifically. And yet there are still many scientists, not to mention a large section of the general public, who do not believe such phenomena even exist. Clearly the phenomena are highly elusive. But still the general public report anomalies and still they cry out for explanation.

On the defensive for so long, many investigators content themselves with ‘proving’ that something paranormal has occurred in a case they are researching. They do this by proving that something ‘cannot have happened by any known normal means’. This rather negative process is always open to the problem that someone will one day discover just such a ‘normal means’ to retrospectively explain the case. What is even worse, such an investigative process makes no great attempt to find out how paranormal phenomena might actually work.

The trouble with most cases is that they are based purely on the evidence of what someone witnessed. We know enough about the unreliability of witnesses to realise it is difficult to build a solid theory on such evidence. People are sadly, for a variety of reasons, not reliable recorders of their surroundings. What is really needed is objective, corroboratory evidence.

This is where instrumentation comes in. It is one thing for someone to claim they saw a ghost. It is quite another for them to produce a photograph of one. While people are subject to innumerable influences, both physical and mental, that are still barely understood, a camera is a known quantity. We know its capabilities and its limitations. Also, a photographic negative can be studied at leisure after the event. Someone’s experience can only be accessed through their, often faulty and changing, memory, which cannot (yet) be put into a laboratory and analysed.

These environmental influences are important because they might:

a) be the cause of some paranormal phenomena

b) be misidentified by witnesses as paranormal

c) cause witnesses to hallucinate ‘paranormal’ phenomena

d) actually be produced BY paranormal phenomena

The last point is not often considered by researchers. For instance, some people think that poltergeist phenomena are produced by people somehow causing physical changes to their environment. Such changes cannot be readily explained by current physical theories. However, one commonly observed factor in physical processes is that they are rarely, if ever, 100% efficient (eg. a light bulb produces a lot of heat as well as light). If a paranormal phenomenon is capable of teleporting an object (such as an apport), which would require a lot of energy, it might result in an accompanying burst of ‘waste’ electromagnetic radiation. This would be a byproduct of the main process, like the waste heat from power stations. If such phenomena really occur, we could try to detect any ‘waste’ radiation that might accompany them.

So, what are the problems?

Far more serious than phenomena being ‘dampened down’ is the problem of misunderstanding the equipment itself. Few investigators are likely to be trained scientists and therefore cannot be expected to understand the limitations and proper use of their instruments or even necessarily what they are measuring. It is this gap in understanding that is at the root of the biggest potential problem with instrumentation. It could lead to unjustified claims of explanations for paranormal phenomena or even ‘new’ anomalies. Luckily there is a cure to this problem - a proper understanding of the instruments and the quantities they measure.

Understanding what you’re measuring

Unfortunately, it is necessary to have some idea of what you are measuring before you can decide what is normal and what abnormal. In the case of electromagnetic (EM) radiation it all starts with the humble electron. This is the particle that orbits atomic nuclei to form atoms. When allowed to flow freely, as in electrical conductors such as metals (where outer electrons are only loosely bound to their atoms), they produce an electric current. Such electric currents produce a magnetic field (eg. there will be one around a mains cable).

Electrons also give rise to static magnetic fields. When electrons in certain materials ‘align’ they produce a strong static magnetic field. The best known example of this is iron (and some alloys such as steel) which can form permanent magnets. The Earth has a static magnetic field produced by processes deep within its core. The effect is the same as a weak permanent magnet. Though generally stable, the Earth’s magnetic field does vary, particularly during electromagnetic ‘storms’ (when unusually high numbers of energetic particles are spat out by the Sun). Static magnetic fields produce a force that can move objects. Unlike electrostatic fields, there is no limit on how strong static magnetic fields can get (though strong fields are extremely rare in the natural environment). Their effect on other materials varies hugely. Iron and its alloys are affected strongly, whereas most other common materials are not.

When electrons move (eg. in electrical conductors) things really get interesting. The motion of the electron gives rise to a magnetic field. Similarly, a conductor moving in the field of a permanent magnet will induce electrons to move inside it, so giving rise to an electric current (as happens in an electric generator). Such varying or moving electric or magnetic fields are sometimes collectively described as AC (for ‘alternating current’ - a reference to the equipment that commonly produces them).

It is important to note, though, that moving fields cannot usually move objects. If you think about it, it is obvious. Imagine a small magnet in a magnetic field that is changing direction five times a second. The magnet will try to move in opposite directions five times in a second. It is not likely to get very far. When you take inertia into account, it is unlikely to move at all.

By varying electromagnetic fields you introduce another variable to record - frequency. This is measured in Hz (‘times per second’). This is the number of times a field reverses direction per second. As this frequency increases, the fields behave less and less like fields (with force and direction) and more and more like waves (with no force and much greater range). This is electromagnetic radiation. Over about 100kHz radiation predominates and the waves are known as radio waves. At higher frequencies still radiation changes characteristics again to become such things as light, X-rays or gamma rays.

Measuring Varying (AC) Fields

Most commercially available electromagnetic detectors are aimed at the ‘EM field pollution’ market. They are typically designed to detect sources of electromagnetic fields (that some scientists believe could affect health) in domestic and commercial premises. Most are sensitive to 50-60Hz fields typical of mains electricity supplies. Others are often designed to look for microwaves (eg. from cellphones and leaky microwave ovens) or for inadvertent radio emissions from electronic devices (such as PCs). Unfortunately, it is not possible to design instruments to detect EM over the whole, or even a large chunk, of the entire frequency range.

Having said that, it is still worth owning one of these ‘EM pollution’ instruments as it could provide a natural explanation for a phenomenon. For instance, modern artificial fields might conceivably produce phenomena that resemble paranormal phenomena. Their detection could thus point to possible natural explanations for a reported phenomenon.

There are, however, further things to bear in mind when taking readings with these instruments. There is, for instance, the question of whether readings are what they seem. Remember that ‘EM pollution’ detectors are often most sensitive to 50-60Hz electric or magnetic fields. However, most instruments will also be sensitive, to a lesser degree, to other nearby frequencies. So if you got a reading of 5 microteslas on a meter, it could be indeed be 5 microteslas at just 60Hz. But it might be 10 microteslas at 30Hz which, because the meter is less sensitive at that frequency, it reports as 5 microteslas. Most likely of all it will represent an average over a broad range of frequencies. So it is difficult to say exactly what such a reading of 5 microteslas represents precisely.

Ideally, for varying fields, you should use a detector that incorporates some kind of spectrum analyser. It would then be possible to produce a graph of field strengths against frequency. Such an instrument would be really worthwhile! However, it would not be cheap. Alternatively, you could always build something from reasonably cheap components if you have a good practical understanding of electronics.

You can get detectors to measure static fields, though they tend to be expensive. Static fields are definitely produced naturally and so might indeed be associated with long-reported anomalous phenomena. The most pervasive source of magnetic fields is the Earth’s field. It tends to be fairly constant at any particular place (except during solar storms). Other significant natural sources of static magnetic fields include certain minerals, such as magnetite. There are many natural sources of static electric fields. Just rubbing two objects together can build up charges. We are all familiar with getting minor shocks when touching metal objects. Lightning is also a natural source of static electric fields.

If you have trouble getting hold of cheap static electric and magnetic field detectors, you can at least use a humble compass to indicate the presence and direction of static magnetic fields. If, when you walk across a room in a straight line, the compass needle rotates it will indicate the presence of a local magnetic source. Unfortunately it will give you no idea of the strength of the field. A strong static electric field may be indicated by a smell of ozone (though this is more likely to be produced by malfunctioning electrical equipment). Again, a cheap meter could be built from commercially available components.

Apart from magnitude, static electric and magnetic fields also have direction. This is more difficult to measure than magnitude. It would determine which way an object might move if subjected to a strong field. You can measure the direction of static magnetic fields with a simple compass.

What is normal?

Before going into a real-life investigation it is important that you get to know your instrument. In particular you should satisfy yourself that it is correctly calibrated (ie. giving accurate readings) and that you know what to expect in ‘normal’ situations (ie. where no anomalous phenomena have ever been reported).

If your instrument does not show any figures but only the ‘presence’ of fields (eg. by way of a light being on), I’m afraid it is of limited use in investigations. Such instruments are designed to see if fields exceed a particular threshold. Unfortunately, even if you know what this threshold is, you cannot tell if the field is twice or three times that value or indeed half as much.

One important tip is that most electromagnetic meters are sensitive (even AC field ones) to static electricity and YOU are a potent source. Therefore, put the meter down and don’t touch it for, say, 10 seconds. The reading should then stabilize and will probably be a lot less than when you are carrying the equipment around. This will be a much truer reading, and you should always use meters in this way.

A particularly useful technique is to check similar locations ‘after the event’. For instance, if you go on a vigil to a pub and find a potent source of AC fields in the cellar, it might seem highly significant (especially if a ghost has been seen there). But might not most pub cellars have similar readings? There are often pumps and other heavy electrical equipment in pub cellars. So try to go to a few others, not known to be haunted, and see if they give similar readings.

When on an investigation it is, of course, most important to identify the sources of any electromagnetic fields. Usually this can be done visually (simply looking for electrical equipment). Sources may not, however, always be obvious. They could be behind walls, eg. mains cabling which emits magnetic fields. If you cannot trace any source internal to a building you might try switching off the power to a room, or even the whole building, to see if the field drops. I hasten to say this should only be done with the permission of the building owner or manager. Even if they agree you should consider if switching off all the power might disrupt permanently powered equipment, timeswitches or machines sensitive to powercuts, such as computers. If you CAN get the mains switched off, you might be able to locate any external sources of electromagnetic fields.

Static magnetic fields are rarer than varying ones in domestic situations. The Earth’s magnetic field will be present (unless shielded somehow - eg. by metal in walls) but it is very weak, between 30 (at the equator) and 60 (at the poles) microteslas. Various household devices have permanent magnets in them, eg. loudspeakers or anything with a motor of some sort in it. Some appliances also contain electromagnets (eg. as relays) that produce static fields when activated. The magnets in these devices will be much stronger than the Earth’s magnetic field but still usually far too weak to, say, move even a nearby light iron object. Typical values for such devices might be a few thousand microteslas.

Static electric fields in domestic situations are usually caused by friction. It can depend heavily on the type of materials used in the room. A typical room might produce up to around 5V/m. If a thunderstorm was going on outside it might be up to 100V/m.

Using meters outside tends to give very low (or nil) readings due to the low density of natural or artificial sources of EM. At a distance of 15m a 500kV overhead power line only yields typically between 3 and 6 microteslas (magnetic). Interestingly, if you live near overheadpower lines you are likely to receive higher field exposure from your domestic appliances than from the power lines (though, of course, most appliances are only used for short periods whereas power lines are always on).

Though nothing to do with electromagnetic fields, I must mention infrasound. This is because it has recently been discovered (see Journal of the Society of Psychical Research, volume 64.3, number 860, July 2000) that infrasound with a frequency of 19Hz can induce feelings anxiety and dizziness. If this frequency is present at significant levels (eg. as a resonating standing wave) it could produce reports of hauntings (eg. feelings of a ‘presence’). This is certainly something we should look for on investigations.

Comments

This article merely scratches the surface of the issues involved in using instrumentation on investigations. While it is not the intention to discourage anyone from using instrumentation, I hope the article has illustrated the complexity of the subject. I hope it will make people think a little before making claims based purely on apparently abnormal instrument readings.

Units

The units used in electromagnetic field measurement can be confusing. Firstly, if the field is varying you will need to specify the frequency being measured in Hz (ie. per second). Electric field strength, whether varying or not, is measured in volts per metre or V/m. Magnetic field strength (strictly speaking, flux density) is usually quoted nowadays in microteslas. Unfortunately, many people use the older unit of the milligauss, which causes endless confusion. Please stick to microteslas if you can. To convert, 10 milligauss = 1 microtesla. Incidentally, the units gauss and tesla are not commonly used as they are both very large by everyday standards.