Stronger & Deepeer Than A Regular Metal Detector
Most conventional metal detectors require you to constantly move a coil over the ground as they energize the coil with current. This creates an artificial magnetic field that is constantly collapsing as it reacts to metal objects with a delayed electric spike. This spike is what causes the metal detector to give off a beep to let you know something metal lies below! This process turns the detector into a tuned receiver that searches for these small spikes of target detection and it reoccurs many times within a second.
While this is a useful way of detecting metal, this form of metal detection is limited by physics. The artificial magnetic field is constantly collapsing and the detection of these spikes is only possible in very close proximity to the coil – rarely more than twice the diameter of the coil you’re using. This is where the Proton Magnetometers are invaluable.
Deeper Than A Regular Metal Detector
Discovery Proton Magnetometers have a huge edge over conventional detectors. These absolute Proton Magnetometers use the Earth’s natural magnetic field to sense and alert you to ferrous targets. They utilize “Gamma readings” – different frequencies around the world that create the Earth’s magnetic field – and produce a value that is an actual measurement of the disturbance in the Earth’s natural, magnetic force. This enables you to take out a Proton Magnetometer and simply read the frequency of the field through the sensor. An increase or decrease in the field means there is metal nearby!
The best part is that Proton Magnetometers don’t transmit anything. Instead they create a small, artificial magnetic field at the sensor coil for one second and then let it collapse. The coil in the sensor then picks up the frequency of the Proton’s as they scramble to re-align themselves back to the natural field. This allows the Proton Magnetometer to find distortions created in the Earth’s natural and fairly even, Gamma field. The larger the metal target is in mass and weight, the farther away from the object this distortion occurs. By this method ferrous metal is naturally intensified by the lines that create the Earth’s magnetic field.
If you are walking around a large field in Central Florida with no ferrous metal close by the Discovery Tone Magnetometer may read a Gamma value of 47,000. It will hold that value, plus or minus
2 or 3 Gammas, as that is the value of the Earth’s natural magnetic field in its undisturbed state.
In the distance you see a 55 gallon drum and you begin to walk towards it with the Magnetometer by your side. The 55 gallon drum will create a distortion of Protons in the Earth’s natural magnetic field – This causes the Gamma readout to change. As you walk towards the drum, you will get closer and closer to the field of distortion created by the drum’s size and weight.
When you’ve reached the edge of that field the Gamma value readout (In addition to the audio alert if you’re using the 1A Fast) will alert you that there is a ferrous object close by. When you are about 30 feet from the drum, the readout will increase by 3 Gammas to 47,003.
As you continue walking and are about 15 feet from the drum, the tone in the earphones will step up in frequency and the gamma value readout will continue to change. Since magnetometers detect your distance from a target by a factor of 8, and the Gamma readout value is increasing in values of 3, you will notice the Gamma readout change to 47,024 (3 x 8 = 24, and the normal Gamma readout for this area is 47,000). Such an increase in the Gamma value is an unmistakable target.
If you walk away from the drum, approximately 35 feet, you will leave the field of distortion created by the drum and your Gamma readout will return to the natural value of the Earth’s magnetic field – In this case: 47,000 Gammas.
If you walk around the drum you will notice the field of distortion extends on every side – Meaning your magnetometer will recognize the drum from every side, even above it or underneath it!
Of course the most productive way to check an area for a ferrous object is by “mowing the lawn” – Or walking up and down the area in straight lines, spaced about 40 feet apart. This increase in the initial Gamma value (in our example it was 3) can indicate how large the target is – the higher the number, the bigger the object. It will increase in factors of 8 as you get closer and closer to the object. This is important to remember when trying to determine the size of the object you’ve detected.
While this example is of the land version of the Tone Magnetometer, the same principles apply for the boat-towed and underwater versions of these machines.