NATURAL EMF TRIFIELD METER

The TriField Natural EM Meter was designed to do field measurements for special research. It detects changes in extremely weak static (DC or "natural") electric and magnetic fields, and signals with both a tone and the movement of a needle-type gauge if either the electric or magnetic field changes from previous levels. A radio and microwave detector is also included, which reads radio power directly. Because man-made AC electric and magnetic fields are very common and could interfere with readings of static fields, the meter has been designed to ignore AC fields. Normal construction materials don't block magnetic fields, so the meter can be placed indoors and will work equally well, and due to the built-in tone, it can be used in the dark, and will sound the tone at whatever level of field the user sets. Model 1 operates on a standard 9-volt battery, and Model 2 runs on a 9-volt battery or an AC adapter (both included). Model 2 has an input jack for an optional high-sensitivity magnetic coil. Both models are covered by a one-year warranty.

MAGNETIC MEASUREMENTS

The meter is sensitive to changes of as little as 0.5% of the strength of the Earth's magnetic field, and the tone will sound whether the field increases or decreases. Model 2 is sensitive down to 0.05% of the Earth's magnetic field when the optional external coil is used. After the meter detects an event, when the magnetic field then becomes stable for more than about five seconds, the tone will stop and the needle will return to zero. The meter will remain at rest until the field changes again. The threshold level (squelch level) of the tone is adjustable. The user determines the amount of change in the magnetic field required to sound the tone. If the field changes by the threshold amount, the tone will come on at a low pitch. If the amount of change is larger, the tone's pitch will be higher. This meter can also be used to determine if anything is magnetized. For example, if a bed frame is magnetized, the meter can be held vertically and slowly be swept by hand over the bed. Any changes in the direction or strength of the magnetic field will register. A similar process can reveal the presence of magnetic rocks just below the ground.

The Natural EM Meter can detect geomagnetic storms caused by unusual solar activity interacting with the ionosphere (which results in rapid changes of up to 10% in the Earth's magnetic field), as well as the electrical activity of ordinary thunderstorms. It will signal the movement of any distant, strong magnetic sources in the sky, even if the sky is cloudy or the source dips behind a hill. Ball lightning should in theory be associated with a strong magnetic field, and magnetization of metal on the ground has been reported with some sightings of unusual lights in the sky.

ELECTRICAL MEASUREMENTS

When the dial is set to ELECTRIC, the meter is sensitive to electric fields as weak as 3 V/m (volts per meter). Indoors, electric fields typically fluctuate 1 or 2 V/m. By setting the minimum sensitivity to change at 3 V/m, we have designed the meter to disregard this "background noise". A 3V/m field is so feeble that if a 10'x10'x10' room were filled with a field of this strength, it would contain the total amount of energy equivalent to that required to lift a single grain of table salt 1/50th of an inch.

Human beings and animals usually emit an electric field which is easily detectable using the Natural EM Meter. In fact, the meter can be used as a motion-activated intruder alarm. It is so sensitive that it can detect the presence of a person through a wall. Though it is not foolproof in this capacity, (sometimes a person will carry no electric charge and thus be "invisible" to the meter), its sensitivity is of interest to researchers in the field of parapsychology. Every type of detectable physical manifestation requires a certain amount of energy. For example, "moving air" requires the expenditure of a small amount of energy to get the air to move initially.

Below is a table showing several types of effects or fields emitted by people and objects. It also shows the minimum amount of energy required (per cubic foot of air) to set up that effect or field so that it is stronger than typical indoor "background noise" for that effect or field. Clearly the static electric field is the type that requires the least energy to be detectable.

Type of Effect or Field	Energy Needed (watts-seconds)	Emitted by people?	Are instruments needed to detect this?
Heat	30	Yes	Thermal Viewer
Moving Air	1/10,000	Yes	No (can feel this)
Static Magnetic	1/20 million	No	Magnetic Meter
Sound	1/100 million	Yes	No
Light	1/1billion	No	No
Static Electric	1/10 billion	Yes	Electric Meter

RADIO/MICROWAVE MEASUREMENTS

The radio/microwave detector is sensitive from 100,000 to 2.5 billion oscillations per second (100 KHz to 2.5 GHz) and can detect strong or unusual atmospheric electrical activity. It can also detect leaky microwave ovens, cellular or portable phones, walkie-talkies and concealed surveillance bugs. Its minimum and maximum detectable signal strengths are 0.01 milliwatt/cm² and 1 milliwatt/cm² respectively.

SUM

The SUM setting in Model 1 adds together the electric and magnetic fields and detects if either field changes. Model 1 is used to find a disturbance in either type of field, but in the SUM setting it can generally detect if a person approaches to within five or ten feet, even on the other side of a wall. For this reason, Model 1 is preferred for parapsychological research, when, for example, a room to be measured is known to be vacant for an extended period (except for experimenters, who remain relatively still for that period). In Model 2, the SUM setting is magnetic plus radio/microwave (which requires somewhat more battery power to operate than the Model 1 SUM, but Model 2 also has an AC adapter). The SUM setting in Model 2 is for early warning of any unusual atmospheric electromagnetic activity, such as geomagnetic storms or ball lightning. In this setting, it does not falsely trigger when people walk by.

Natural EM Meter Frequency Response Table

Frequency (Hz)	Magnetic Full Scale Equals (RMS milligauss)	Multiply Reading By	Electric Full Scale Equals (RMS Volts/Meter)	Multiply Reading By
.5	330	3.3	2,000	20
1	580	5.8	2,000	20
2	1,000	10	2,300	23
5	1,500	15	2,500	25

10	2,500	25	2,800	28
20	3,000	30	5,000	50
50	3,300	33	16,000	160

100	3,500	35	50,000	500
200	3,500	35
500	3,300	33

1,000	3,000	30
2,000	2,300	23
5,000	2,000	20

10,000	2,500

This gaussmeter, electric field meter, and RF field strength meter combines several EMF spectrums of measurement in one.

The original TriField ^® Meter combines all the features needed for fast, accurate measurements of electromagnetic fields. It independently measures electric field and magnetic field, and is properly scaled to indicate the full magnitude of currents produced by each type of field inside a conductive body. As a result, it "sees" much more than any other electromagnetic pollution meter.

Depending on where the knob is set, the meter detects either frequency- weighted magnetic fields (two separate scales), or frequency-weighted electric fields in the ELF and VLF range. It has significant sensitivity at 100,000 Hz, well past the 17,000 Hz horizontal scan of video displays. The radio/microwave setting can detect up to three billion Hz (3 GHz), which lets you gauge radio- wave power, CB and cellular phone equipment, and many types of radars.

This meter is the only one which combines magnetic, electric, and radio/microwave detectors in one package, so that the entire nonionizing electromagnetic spectrum is covered. In addition, the magnetic setting and the electric setting measure true magnitude, a feature found elsewhere only in more expensive meters. If you hold the meter in the center of a room and tip it to various angles, the magnetic reading will stay approximately the same regardless of which way you tip or rotate it. The electric reading is similar, although the presence of your body alters the actual electric field, so readings will vary more. The radio/microwave setting reads the full power of radiowaves when the meter is pointed toward the source.

Surprisingly, the standard TriField Meter is one of the least expensive meters available. The few other meters below $150 read only low-frequency magnetic fields and only in one direction (not true magnitude). The magnetic section of the TriField meter has three field-detecting coils pointing in the X, Y, and Z directions. A circuit amplifies these signals and gives them the proper frequency-weighting (sensitivity increases linearly from 30 Hz to 500 Hz, but with some residual sensitivity up to 100 MHz). A unique network combines the three coil outputs nonlinearly to approximate a true magnitude. The meter is sensitive from 0.2 to 100 milligauss full scale at 60 Hz (or 0.1 to 50 milligauss full scale at 120 Hz, etc.) with a resolution of 0.2 milligauss in the sensitive range. Accuracy is +/-20% at mid-range. A version with flat frequency response (instead of linear sensitivity increase) is also available for the same price.

The TriField Meter comes with a one-year warranty and a 9-volt transistor battery included. This type of battery lasts about 10 hours (total measurement time). When the BATTERY TEST reads low, the battery can be replaced with any rectangular 9 volt transistor or alkaline (which lasts about 50 hours) type. This meter is manufactured in the USA.

A knob on the front has six positions: OFF, BATTERY TEST, two MAGNETIC field sensitivities (0.5-100 milligauss at 60 Hz, and 0.2-3 milligauss at 60 Hz, the second sensitivity to measure weak fields more accurately), ELECTRIC field and RADIO/MICROWAVE power density. The meter face is analog (needle type). A needle reading of one-third of full scale corresponds to either 3 milligauss (or 0.6 milligauss) @ 60 Hz, 3 kilovolts/meter @ 60 Hz, or 0.04 mW/cm² respectively in the magnetic, electric, and radio/microwave field settings. Average magnetic field strength in North American homes and offices is 1-3 milligauss, so the meter is labeled "HIGH" above these levels.

MAGNETIC FIELD DETECTION

In most homes or offices, some areas are "hot" spots with readings in the HIGH range. Most often, this is caused by magnetic fields, which come largely from unpaired internal wiring. (Contrary to popular belief, power transmission lines and transformers do not generally contribute as much magnetic field as does internal wiring.) Other magnetic sources include video displays, motorized clocks and other equipment, electric blankets and heaters, fluorescent lights and light dimmers, and the transformers that are inside consumer devices. Much of the total field strength is from frequencies that are harmonics or multiples of 60 Hz (120 Hz, 180 Hz, etc.) and 17,000 Hz of video displays. Cars (especially near the front floorboard of electronic ignition cars) and motorcycles have fairly strong fields that are at frequencies higher than 60 Hz. Magnetic field is difficult to shield, but sheet steel is somewhat effective.

ELECTRIC FIELD DETECTION

A few areas in most homes read HIGH in the electric field setting. These include areas near improperly grounded equipment, the front of video screens, and fluorescent lights. Most of these fields can be easily shielded using a grounded metal screen or foil; VDT screens of this type are readily available. You can greatly reduce the strength of an electric field just by placing your hand in front of the source. This effect can be seen using a TriField meter.

MICROWAVE DETECTION

Occasionally, certain areas read HIGH in the radio/microwave setting. These include door seals around microwave ovens, and cellular phones (but not regular radio phones, which are very low-power). Radio/microwaves can be shielded in the same way as electric fields, although the lower frequency radio waves are not shielded by your hand as easily as microwaves are. (Metal screens will shield both.) In the United States, radars and FM transmitters can legally expose residents to moderately high power levels (as high as 10 mW/cm² briefly or .57 mW/cm² near cellular towers), but such exposure is not common.

REDUCING FIELD EXPOSURE

Some equipment is sensitive to magnetic fields (ie, a high resolution color monitor may not function properly above 30 milligauss). By seeing "hot" spots in your home and office, you can move equipment or furniture to reduce exposure. If a room has a "hot" spot, fields are generally much weaker elsewhere in that same room.