An Inclusive Guide About Metal Detector

Metal detector was invented in 1881 and its use since has grown significantly. It’s used in the food industry, health industry mining industry, construction industry military application, courthouse about this technology. This article will provide you with an all-inclusive deal about metal detector.

Common Myths and Facts about Metal Detector

People have come up with varied myths and facts about this technology. The common ones include:


  • Metal detector was invented by Alexander Graham Bell.
  • Doctors use it to diagnose some medical problems.
  •  Many metal detector enthusiasts tend to speak their own unique language. This is because of the jargon.
  • They use that includes words like black dirt, freestyling, canslaw, and joke tags among others. Each of them has unique meaning.


  •  Metal detector usually depends on the x-ray technology. In fact, most of them use very low frequency beat-frequency oscillation and pulse induction.
  • Metal detecting process tears up public places and parks
  • Metal detectorist tend to disturb archeological sites
  • You can freely use your metal detector anywhere you want. You must respect privet property laws among other regulations
  •   Only experts use it to find valuables.

Types of Metal detectors

These detectors are mainly categorized base on the industry or area of use. Some alterations are made to their design so as to fit the specific needs of the target industry. Basically these metal detectors can be categorized as:

1. Ground Searchers

They are made of a grip at the top, control panel, a long rod and a coil at the bottom. They are used to detect ferrous and non-ferrous metal in the soil

2. Handheld Detectors

They are also called pointers or pin pointers and are made of small rods with an added handgrip. As the name suggest they are held in an operator hand and help detect metals above the ground or on an individual.

3. Footwear Detectors

These are wearable devices made of straps. As one walks, these detectors work and can help detect up to 4 inches in dirt sand and grass.

4. Plant Detectors

These are the most complex ones and are fitted in various machines to help detect metal in food industry among other unique need. There is no one standard design for them, but are fitted to address the specific needs of the production process.

  • Causes of Metal Detector False Rejects and Tips on How to Solve Them
  • Just like any other technology, the use of metal detector whether its simple or sophisticated systems
  • May result in several false rejects. This false rejects can cause so much wastage, wrong diagnosis, slowing down of the production process
  • Causes of Metal Detector False Rejects and Tips on How to Solve Them

Just like any other technology, the use of metal detector whether its in simple or sophisticated systems may result in several false rejects. This false rejects can cause so much wastage, wrong diagnosis, slowing down of the production process, among others depending on which industry its used in.

This rejects are usually caused by the following:

1. Conveyor System Issues

This is common when metal detector is being used in production lines and the company’s conveyor system has some mechanical problems. Maybe its metal detector heads aren’t set correctly or it has a loose fitting All this will cause many false rejects. To avoid this, ascertain that any new component installed in this system is fitted per manufactures specifications. Also service your systems regularly and before production ensure that the conveyor is in a perfect state.

2. Radio Frequency Interference

Many metal detector units tend to operate via a radio frequency system. Metal detection radio waves can be interfered with just like solid structures and electric lines may interfere with the signal reception of your AM radio. Also presence of other detectors in the neighborhood can affect these waves. All these could cause improper reception of the correct radio waves resulting to false rejects. It’s advisable to recheck your radio wave results every hour so as to identify any problems and how to solve them.

3. Product Uniformity

Humidity and temperature change may cause the conductivity of some products. This affects the way radio frequencies pass through them. This is likely to result false rejects. To avoid this, try regulating the environmental conditions in your production room and also using automatic detection technology as a means of reducing this rejects.

4. Automatic Adjustments

Most manufactures are using systems that have automatic adjustments points. If they aren’t turned on or appropriately calibrated, they may cause false rejects. Avoid this by always utilizing higher-tech setting of these machines.

5. Footwear That Have Metal Accents

If your shoe laces have metal eyelets, or your footwear has a steel area, it may turn off some detectors. Just ensure that you are dressed appropriately when carrying out metal detection.

Tips to Help Achieve Reliable Long-team Performance with Your Metal Detector

  • Remove any possible vibration on this detector. A detectors sensitivity reduces when even a smaller movement on its transmit receive coils is noted.
  •  Ensure that it’s not receiving any noisy power. Most detectors send a false reject when it senses noise spikes.
  •  Ensure that any variable frequency derives in the processing manufacturing line aren’t talking to your installed detectors.
  •  Ensure that your detectors control setting correctly match to product or other’s needs.
  •  Your conveying system must never be contaminated with any metal.
  •  Any calibrations and preventive maintenance should be done by expert.
  •  Constantly test it for the worst case detection scenario and fic if need be.
  •  Regularly test your reject device.

Controversy Brought by the Halo Effect Theory and Metal Detectors.

The fresh burial test for many coins tends to leave many metal detectors owners imagine that they either bought the wrong coin or their machine is faulty. A genuine coin buried about 6 inches in the soil will not send any signal on your metal detector 10 minutes later. This is because of the known halo effect theory. It states that, any buried metal objects buried long ego usually have something unique and can never be duplicated using a test garden that has been created recently.

Another controversy comes with the imagination that its only iron objects that form a halo. That gold, silver and copper wont form any halo because they are so inert significantly react in very few years of constant soil contact. This is because when they are dug, especially silver; most of them aren’t corroded or pitted significantly. You can understand this skepticism because palladium, platinum, gold, copper and silver are all classified as noble (low reactivity) in chemistry terms. Not going into details, science has revealed that gold, copper and silver exhibit this halo effect.

With this information, you are sure of what to expect when dealing with metal detection.

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