EMF Detectors – Basics on Field/Poles

One of the most important things for investigators to know about EMF detectors is that there are three primary types: single field/pole, dual field/pole, and tri field/pole.

Detector Polarity

As with magnets, detector elements have a polarity. Now since we live in a three dimensional world, a magnetic source can be polarized in any of the three axis (x, y, z), or a combination of the three.

Single Field/Pole Detectors

Single field/pole detectors are the trickiest to use if an investigator is trying to get accurate EMF data.  The reason being is that they are polarized to a single field.  For example:  
  If I have a detector that is polarized vertically then any EMF that has waves vertically polarized will produce the highest readings; likewise any EMF that is horizontally polarized will produce a much lower reading.  Both EMFs could be of the same strength, but the one that matches the polarity of the detectors receiving element will display the highest reading.

This is why I have to shake my head when I see investigators taking measurements while constantly changing the polarity of the detector element, and what’s worse is when they get a reading they believe is significant and try to determine the affected area and then move the detector around, changing the polarity of the detector and claim the readings drop off.  Well of course they do since they changed the polarity and now the meters polarity doesn’t match the source anymore.

This is the main reason I try to urge investigators to spend the money on a good tri-field detector, which we’ll get to in a moment.

Dual Field/Pole Detectors

Dual field/pole detectors are better for accuracy, but still have issues with polarity since they only cover two of the three axis.  But, because they do cover two axis they can be useful in determining the direction of the EMF source, and if two are employed at the same time they may be used to triangulate on the EMF source and pinpoint the location.  This is not to say that they are guaranteed to do this since it is a learned skill, they do provide the possibility of using them in such a manner.

But, because they do employ two detectors that are polarized 90 degrees to one another, the are better at getting a more accurate measurement and less likely to fool the investigator using the device.

Tri Field/Pole Detector

This is the best meter for getting an accurate measurement without having to put in much effort about checking polarities, and it is not prone to the polarity issues that the other two face.  In essence, it is omnidirectional and will give a fairly consistent reading regardless of the polarity relationship.  This is why I highly recommend this type of meter to investigators since it does not require the constant attention to polarity that the single field/pole or dual field/pole detectors need.

For baseline measurements, tri field/pole detectors can’t be beat because of the omnidirectional properties.  Since orientation makes little difference, investigators are free to walk a room and take measurements without worrying about pole orientation when they turn, raise or lower the meter, or when they hold it upright to better view the measurement.  Experience level becomes much less of an issue, which makes this an ideal meter for the beginner, and for the seasoned investigator it helps take away some of the burden as it removes the attention to detail required with other types of meters.